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linux/lib/radix-tree.c

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Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
Christoph has moved Remove all clameter@sgi.com addresses from the kernel tree since they will become invalid on June 27th. Change my maintainer email address for the slab allocators to cl@linux-foundation.org (which will be the new email address for the future). Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04 09:59:22 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: small Reduce radix tree node memory usage by about a factor of 4 for small files (< 64K). There are pointer traversal and memory usage costs for large files with dense pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree documentation cleanups Documentation changes to help radix tree users avoid overrunning the tags array. RADIX_TREE_TAGS moves to linux/radix-tree.h and is now known as RADIX_TREE_MAX_TAGS (Nick Piggin's idea). Tag parameters are changed to unsigned, and some comments are updated. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 03:08:05 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
fix the max path calculation in radix-tree.c A while back, Nick Piggin introduced a patch to reduce the node memory usage for small files (commit cfd9b7df4abd3257c9e381b0e445817b26a51c0c): -#define RADIX_TREE_MAP_SHIFT 6 +#define RADIX_TREE_MAP_SHIFT (CONFIG_BASE_SMALL ? 4 : 6) Unfortunately, he didn't take into account the fact that the calculation of the maximum path was based on an assumption of having to round up: #define RADIX_TREE_MAX_PATH (RADIX_TREE_INDEX_BITS/RADIX_TREE_MAP_SHIFT + 2) So, if CONFIG_BASE_SMALL is set, you will end up with a RADIX_TREE_MAX_PATH that is one greater than necessary. The practical upshot of this is just a bit of wasted memory (one long in the height_to_maxindex array, an extra pre-allocated radix tree node per cpu, and extra stack usage in a couple of functions), but it seems worth getting right. It's also worth noting that I never build with CONFIG_BASE_SMALL. What I did to test this was duplicate the code in a small user-space program and check the results of the calculations for max path and the contents of the height_to_maxindex array. Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:49 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
fix the max path calculation in radix-tree.c A while back, Nick Piggin introduced a patch to reduce the node memory usage for small files (commit cfd9b7df4abd3257c9e381b0e445817b26a51c0c): -#define RADIX_TREE_MAP_SHIFT 6 +#define RADIX_TREE_MAP_SHIFT (CONFIG_BASE_SMALL ? 4 : 6) Unfortunately, he didn't take into account the fact that the calculation of the maximum path was based on an assumption of having to round up: #define RADIX_TREE_MAX_PATH (RADIX_TREE_INDEX_BITS/RADIX_TREE_MAP_SHIFT + 2) So, if CONFIG_BASE_SMALL is set, you will end up with a RADIX_TREE_MAX_PATH that is one greater than necessary. The practical upshot of this is just a bit of wasted memory (one long in the height_to_maxindex array, an extra pre-allocated radix tree node per cpu, and extra stack usage in a couple of functions), but it seems worth getting right. It's also worth noting that I never build with CONFIG_BASE_SMALL. What I did to test this was duplicate the code in a small user-space program and check the results of the calculations for max path and the contents of the height_to_maxindex array. Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:49 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] slab: remove kmem_cache_t Replace all uses of kmem_cache_t with struct kmem_cache. The patch was generated using the following script: #!/bin/sh # # Replace one string by another in all the kernel sources. # set -e for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do quilt add $file sed -e "1,\$s/$1/$2/g" $file >/tmp/$$ mv /tmp/$$ $file quilt refresh done The script was run like this sh replace kmem_cache_t "struct kmem_cache" Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:20 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
radix-tree: fix small lockless radix-tree bug We shrink a radix tree when its root node has only one child, in the left most slot. The child becomes the new root node. To perform this operation in a manner compatible with concurrent lockless lookups, we atomically switch the root pointer from the parent to its child. However a concurrent lockless lookup may now have loaded a pointer to the parent (and is presently deciding what to do next). For this reason, we also have to keep the parent node in a valid state after shrinking the tree, until the next RCU grace period -- otherwise this lookup with the parent pointer may not do the right thing. Notably, we need to keep the child in the left most slot there in case that is requested by the lookup. This is all pretty standard RCU stuff. It is worth repeating because in my eagerness to obey the radix tree node constructor scheme, I had broken it by zeroing the radix tree node before the grace period. What could happen is that a lookup can load the parent pointer, then decide it wants to follow the left most child slot, only to find the slot contained NULL due to the concurrent shrinker having zeroed the parent node before waiting for a grace period. The lookup would return a false negative as a result. Fix it by doing that clearing in the RCU callback. I would normally want to rip out the constructor entirely, but radix tree nodes are one of those places where they make sense (only few cachelines will be touched soon after allocation). This was never actually found in any lockless pagecache testing or by the test harness, but by seeing the odd problem with my scalable vmap rewrite. I have not tickled the test harness into reproducing it yet, but I'll keep working at it. Fortunately, it is not a problem anywhere lockless pagecache is used in mainline kernels (pagecache probe is not a guarantee, and brd does not have concurrent lookups and deletes). Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-12 15:21:52 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: avoid atomic allocations for preloaded insertions Most pagecache (and some other) radix tree insertions have the great opportunity to preallocate a few nodes with relaxed gfp flags. But the preallocation is squandered when it comes time to allocate a node, we default to first attempting a GFP_ATOMIC allocation -- that doesn't normally fail, but it can eat into atomic memory reserves that we don't need to be using. Another upshot of this is that it removes the sometimes highly contended zone->lock from underneath tree_lock. Pagecache insertions are always performed with a radix tree preload, and after this change, such a situation will never fall back to kmem_cache_alloc within radix_tree_node_alloc. David Miller reports seeing this allocation fail on a highly threaded sparc64 system: [527319.459981] dd: page allocation failure. order:0, mode:0x20 [527319.460403] Call Trace: [527319.460568] [00000000004b71e0] __slab_alloc+0x1b0/0x6a8 [527319.460636] [00000000004b7bbc] kmem_cache_alloc+0x4c/0xa8 [527319.460698] [000000000055309c] radix_tree_node_alloc+0x20/0x90 [527319.460763] [0000000000553238] radix_tree_insert+0x12c/0x260 [527319.460830] [0000000000495cd0] add_to_page_cache+0x38/0xb0 [527319.460893] [00000000004e4794] mpage_readpages+0x6c/0x134 [527319.460955] [000000000049c7fc] __do_page_cache_readahead+0x170/0x280 [527319.461028] [000000000049cc88] ondemand_readahead+0x208/0x214 [527319.461094] [0000000000496018] do_generic_mapping_read+0xe8/0x428 [527319.461152] [0000000000497948] generic_file_aio_read+0x108/0x170 [527319.461217] [00000000004badac] do_sync_read+0x88/0xd0 [527319.461292] [00000000004bb5cc] vfs_read+0x78/0x10c [527319.461361] [00000000004bb920] sys_read+0x34/0x60 [527319.461424] [0000000000406294] linux_sparc_syscall32+0x3c/0x40 The calltrace is significant: __do_page_cache_readahead allocates a number of pages with GFP_KERNEL, and hence it should have reclaimed sufficient memory to satisfy GFP_ATOMIC allocations. However after the list of pages goes to mpage_readpages, there can be significant intervals (including disk IO) before all the pages are inserted into the radix-tree. So the reserves can easily be depleted at that point. The patch is confirmed to fix the problem. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-04 22:29:10 -08:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: avoid atomic allocations for preloaded insertions Most pagecache (and some other) radix tree insertions have the great opportunity to preallocate a few nodes with relaxed gfp flags. But the preallocation is squandered when it comes time to allocate a node, we default to first attempting a GFP_ATOMIC allocation -- that doesn't normally fail, but it can eat into atomic memory reserves that we don't need to be using. Another upshot of this is that it removes the sometimes highly contended zone->lock from underneath tree_lock. Pagecache insertions are always performed with a radix tree preload, and after this change, such a situation will never fall back to kmem_cache_alloc within radix_tree_node_alloc. David Miller reports seeing this allocation fail on a highly threaded sparc64 system: [527319.459981] dd: page allocation failure. order:0, mode:0x20 [527319.460403] Call Trace: [527319.460568] [00000000004b71e0] __slab_alloc+0x1b0/0x6a8 [527319.460636] [00000000004b7bbc] kmem_cache_alloc+0x4c/0xa8 [527319.460698] [000000000055309c] radix_tree_node_alloc+0x20/0x90 [527319.460763] [0000000000553238] radix_tree_insert+0x12c/0x260 [527319.460830] [0000000000495cd0] add_to_page_cache+0x38/0xb0 [527319.460893] [00000000004e4794] mpage_readpages+0x6c/0x134 [527319.460955] [000000000049c7fc] __do_page_cache_readahead+0x170/0x280 [527319.461028] [000000000049cc88] ondemand_readahead+0x208/0x214 [527319.461094] [0000000000496018] do_generic_mapping_read+0xe8/0x428 [527319.461152] [0000000000497948] generic_file_aio_read+0x108/0x170 [527319.461217] [00000000004badac] do_sync_read+0x88/0xd0 [527319.461292] [00000000004bb5cc] vfs_read+0x78/0x10c [527319.461361] [00000000004bb920] sys_read+0x34/0x60 [527319.461424] [0000000000406294] linux_sparc_syscall32+0x3c/0x40 The calltrace is significant: __do_page_cache_readahead allocates a number of pages with GFP_KERNEL, and hence it should have reclaimed sufficient memory to satisfy GFP_ATOMIC allocations. However after the list of pages goes to mpage_readpages, there can be significant intervals (including disk IO) before all the pages are inserted into the radix-tree. So the reserves can easily be depleted at that point. The patch is confirmed to fix the problem. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-04 22:29:10 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: avoid atomic allocations for preloaded insertions Most pagecache (and some other) radix tree insertions have the great opportunity to preallocate a few nodes with relaxed gfp flags. But the preallocation is squandered when it comes time to allocate a node, we default to first attempting a GFP_ATOMIC allocation -- that doesn't normally fail, but it can eat into atomic memory reserves that we don't need to be using. Another upshot of this is that it removes the sometimes highly contended zone->lock from underneath tree_lock. Pagecache insertions are always performed with a radix tree preload, and after this change, such a situation will never fall back to kmem_cache_alloc within radix_tree_node_alloc. David Miller reports seeing this allocation fail on a highly threaded sparc64 system: [527319.459981] dd: page allocation failure. order:0, mode:0x20 [527319.460403] Call Trace: [527319.460568] [00000000004b71e0] __slab_alloc+0x1b0/0x6a8 [527319.460636] [00000000004b7bbc] kmem_cache_alloc+0x4c/0xa8 [527319.460698] [000000000055309c] radix_tree_node_alloc+0x20/0x90 [527319.460763] [0000000000553238] radix_tree_insert+0x12c/0x260 [527319.460830] [0000000000495cd0] add_to_page_cache+0x38/0xb0 [527319.460893] [00000000004e4794] mpage_readpages+0x6c/0x134 [527319.460955] [000000000049c7fc] __do_page_cache_readahead+0x170/0x280 [527319.461028] [000000000049cc88] ondemand_readahead+0x208/0x214 [527319.461094] [0000000000496018] do_generic_mapping_read+0xe8/0x428 [527319.461152] [0000000000497948] generic_file_aio_read+0x108/0x170 [527319.461217] [00000000004badac] do_sync_read+0x88/0xd0 [527319.461292] [00000000004bb5cc] vfs_read+0x78/0x10c [527319.461361] [00000000004bb920] sys_read+0x34/0x60 [527319.461424] [0000000000406294] linux_sparc_syscall32+0x3c/0x40 The calltrace is significant: __do_page_cache_readahead allocates a number of pages with GFP_KERNEL, and hence it should have reclaimed sufficient memory to satisfy GFP_ATOMIC allocations. However after the list of pages goes to mpage_readpages, there can be significant intervals (including disk IO) before all the pages are inserted into the radix-tree. So the reserves can easily be depleted at that point. The patch is confirmed to fix the problem. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-04 22:29:10 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: avoid atomic allocations for preloaded insertions Most pagecache (and some other) radix tree insertions have the great opportunity to preallocate a few nodes with relaxed gfp flags. But the preallocation is squandered when it comes time to allocate a node, we default to first attempting a GFP_ATOMIC allocation -- that doesn't normally fail, but it can eat into atomic memory reserves that we don't need to be using. Another upshot of this is that it removes the sometimes highly contended zone->lock from underneath tree_lock. Pagecache insertions are always performed with a radix tree preload, and after this change, such a situation will never fall back to kmem_cache_alloc within radix_tree_node_alloc. David Miller reports seeing this allocation fail on a highly threaded sparc64 system: [527319.459981] dd: page allocation failure. order:0, mode:0x20 [527319.460403] Call Trace: [527319.460568] [00000000004b71e0] __slab_alloc+0x1b0/0x6a8 [527319.460636] [00000000004b7bbc] kmem_cache_alloc+0x4c/0xa8 [527319.460698] [000000000055309c] radix_tree_node_alloc+0x20/0x90 [527319.460763] [0000000000553238] radix_tree_insert+0x12c/0x260 [527319.460830] [0000000000495cd0] add_to_page_cache+0x38/0xb0 [527319.460893] [00000000004e4794] mpage_readpages+0x6c/0x134 [527319.460955] [000000000049c7fc] __do_page_cache_readahead+0x170/0x280 [527319.461028] [000000000049cc88] ondemand_readahead+0x208/0x214 [527319.461094] [0000000000496018] do_generic_mapping_read+0xe8/0x428 [527319.461152] [0000000000497948] generic_file_aio_read+0x108/0x170 [527319.461217] [00000000004badac] do_sync_read+0x88/0xd0 [527319.461292] [00000000004bb5cc] vfs_read+0x78/0x10c [527319.461361] [00000000004bb920] sys_read+0x34/0x60 [527319.461424] [0000000000406294] linux_sparc_syscall32+0x3c/0x40 The calltrace is significant: __do_page_cache_readahead allocates a number of pages with GFP_KERNEL, and hence it should have reclaimed sufficient memory to satisfy GFP_ATOMIC allocations. However after the list of pages goes to mpage_readpages, there can be significant intervals (including disk IO) before all the pages are inserted into the radix-tree. So the reserves can easily be depleted at that point. The patch is confirmed to fix the problem. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-04 22:29:10 -08:00
Remove set_migrateflags() Migrate flags must be set on slab creation as agreed upon when the antifrag logic was reviewed. Otherwise some slabs of a slabcache will end up in the unmovable and others in the reclaimable section depending on which flag was active when a new slab page was allocated. This likely slid in somehow when antifrag was merged. Remove it. The buffer_heads are always allocated with __GFP_RECLAIMABLE because the SLAB_RECLAIM_ACCOUNT option is set. The set_migrateflags() never had any effect there. Radix tree allocations are not directly reclaimable but they are allocated with __GFP_RECLAIMABLE set on each allocation. We now set SLAB_RECLAIM_ACCOUNT on radix tree slab creation making sure that radix tree slabs are consistently placed in the reclaimable section. Radix tree slabs will also be accounted as such. There is then no user left of set_migratepages. So remove it. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 02:12:05 -07:00
radix-tree: avoid atomic allocations for preloaded insertions Most pagecache (and some other) radix tree insertions have the great opportunity to preallocate a few nodes with relaxed gfp flags. But the preallocation is squandered when it comes time to allocate a node, we default to first attempting a GFP_ATOMIC allocation -- that doesn't normally fail, but it can eat into atomic memory reserves that we don't need to be using. Another upshot of this is that it removes the sometimes highly contended zone->lock from underneath tree_lock. Pagecache insertions are always performed with a radix tree preload, and after this change, such a situation will never fall back to kmem_cache_alloc within radix_tree_node_alloc. David Miller reports seeing this allocation fail on a highly threaded sparc64 system: [527319.459981] dd: page allocation failure. order:0, mode:0x20 [527319.460403] Call Trace: [527319.460568] [00000000004b71e0] __slab_alloc+0x1b0/0x6a8 [527319.460636] [00000000004b7bbc] kmem_cache_alloc+0x4c/0xa8 [527319.460698] [000000000055309c] radix_tree_node_alloc+0x20/0x90 [527319.460763] [0000000000553238] radix_tree_insert+0x12c/0x260 [527319.460830] [0000000000495cd0] add_to_page_cache+0x38/0xb0 [527319.460893] [00000000004e4794] mpage_readpages+0x6c/0x134 [527319.460955] [000000000049c7fc] __do_page_cache_readahead+0x170/0x280 [527319.461028] [000000000049cc88] ondemand_readahead+0x208/0x214 [527319.461094] [0000000000496018] do_generic_mapping_read+0xe8/0x428 [527319.461152] [0000000000497948] generic_file_aio_read+0x108/0x170 [527319.461217] [00000000004badac] do_sync_read+0x88/0xd0 [527319.461292] [00000000004bb5cc] vfs_read+0x78/0x10c [527319.461361] [00000000004bb920] sys_read+0x34/0x60 [527319.461424] [0000000000406294] linux_sparc_syscall32+0x3c/0x40 The calltrace is significant: __do_page_cache_readahead allocates a number of pages with GFP_KERNEL, and hence it should have reclaimed sufficient memory to satisfy GFP_ATOMIC allocations. However after the list of pages goes to mpage_readpages, there can be significant intervals (including disk IO) before all the pages are inserted into the radix-tree. So the reserves can easily be depleted at that point. The patch is confirmed to fix the problem. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-04 22:29:10 -08:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
radix-tree: fix small lockless radix-tree bug We shrink a radix tree when its root node has only one child, in the left most slot. The child becomes the new root node. To perform this operation in a manner compatible with concurrent lockless lookups, we atomically switch the root pointer from the parent to its child. However a concurrent lockless lookup may now have loaded a pointer to the parent (and is presently deciding what to do next). For this reason, we also have to keep the parent node in a valid state after shrinking the tree, until the next RCU grace period -- otherwise this lookup with the parent pointer may not do the right thing. Notably, we need to keep the child in the left most slot there in case that is requested by the lookup. This is all pretty standard RCU stuff. It is worth repeating because in my eagerness to obey the radix tree node constructor scheme, I had broken it by zeroing the radix tree node before the grace period. What could happen is that a lookup can load the parent pointer, then decide it wants to follow the left most child slot, only to find the slot contained NULL due to the concurrent shrinker having zeroed the parent node before waiting for a grace period. The lookup would return a false negative as a result. Fix it by doing that clearing in the RCU callback. I would normally want to rip out the constructor entirely, but radix tree nodes are one of those places where they make sense (only few cachelines will be touched soon after allocation). This was never actually found in any lockless pagecache testing or by the test harness, but by seeing the odd problem with my scalable vmap rewrite. I have not tickled the test harness into reproducing it yet, but I'll keep working at it. Fortunately, it is not a problem anywhere lockless pagecache is used in mainline kernels (pagecache probe is not a guarantee, and brd does not have concurrent lookups and deletes). Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-12 15:21:52 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] gfp flags annotations - part 1 - added typedef unsigned int __nocast gfp_t; - replaced __nocast uses for gfp flags with gfp_t - it gives exactly the same warnings as far as sparse is concerned, doesn't change generated code (from gcc point of view we replaced unsigned int with typedef) and documents what's going on far better. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-07 07:46:04 +01:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
Remove set_migrateflags() Migrate flags must be set on slab creation as agreed upon when the antifrag logic was reviewed. Otherwise some slabs of a slabcache will end up in the unmovable and others in the reclaimable section depending on which flag was active when a new slab page was allocated. This likely slid in somehow when antifrag was merged. Remove it. The buffer_heads are always allocated with __GFP_RECLAIMABLE because the SLAB_RECLAIM_ACCOUNT option is set. The set_migrateflags() never had any effect there. Radix tree allocations are not directly reclaimable but they are allocated with __GFP_RECLAIMABLE set on each allocation. We now set SLAB_RECLAIM_ACCOUNT on radix tree slab creation making sure that radix tree slabs are consistently placed in the reclaimable section. Radix tree slabs will also be accounted as such. There is then no user left of set_migratepages. So remove it. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 02:12:05 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[LIB]: export radix_tree_preload() XFS filestreams functionality uses radix trees and the preload functions. XFS can be built as a module and hence we need radix_tree_preload() exported. radix_tree_preload_end() is a static inline, so it doesn't need exporting. Signed-Off-By: Dave Chinner <dgc@sgi.com> Signed-Off-By: Tim Shimmin <tes@sgi.com>
2007-07-14 16:05:04 +10:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree documentation cleanups Documentation changes to help radix tree users avoid overrunning the tags array. RADIX_TREE_TAGS moves to linux/radix-tree.h and is now known as RADIX_TREE_MAX_TAGS (Nick Piggin's idea). Tag parameters are changed to unsigned, and some comments are updated. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 03:08:05 -08:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
radix-tree: add gang_lookup_slot, gang_lookup_slot_tag Introduce gang_lookup_slot() and gang_lookup_slot_tag() functions, which are used by lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 19:45:29 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
radix-tree: add gang_lookup_slot, gang_lookup_slot_tag Introduce gang_lookup_slot() and gang_lookup_slot_tag() functions, which are used by lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 19:45:29 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
radix-tree: add gang_lookup_slot, gang_lookup_slot_tag Introduce gang_lookup_slot() and gang_lookup_slot_tag() functions, which are used by lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 19:45:29 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] reiser4: add radix_tree_lookup_slot() Reiser4 uses radix trees to solve a trouble reiser4_readdir has serving nfs requests. Unfortunately, radix tree api lacks an operation suitable for modifying existing entry. This patch adds radix_tree_lookup_slot which returns pointer to found item within the tree. That location can be then updated. Both Nick and Christoph Lameter have patches which need this as well. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 00:59:29 -08:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
[PATCH] reiser4: add radix_tree_lookup_slot() Reiser4 uses radix trees to solve a trouble reiser4_readdir has serving nfs requests. Unfortunately, radix tree api lacks an operation suitable for modifying existing entry. This patch adds radix_tree_lookup_slot which returns pointer to found item within the tree. That location can be then updated. Both Nick and Christoph Lameter have patches which need this as well. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 00:59:29 -08:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
[PATCH] reiser4: add radix_tree_lookup_slot() Reiser4 uses radix trees to solve a trouble reiser4_readdir has serving nfs requests. Unfortunately, radix tree api lacks an operation suitable for modifying existing entry. This patch adds radix_tree_lookup_slot which returns pointer to found item within the tree. That location can be then updated. Both Nick and Christoph Lameter have patches which need this as well. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 00:59:29 -08:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree documentation cleanups Documentation changes to help radix tree users avoid overrunning the tags array. RADIX_TREE_TAGS moves to linux/radix-tree.h and is now known as RADIX_TREE_MAX_TAGS (Nick Piggin's idea). Tag parameters are changed to unsigned, and some comments are updated. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 03:08:05 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree documentation cleanups Documentation changes to help radix tree users avoid overrunning the tags array. RADIX_TREE_TAGS moves to linux/radix-tree.h and is now known as RADIX_TREE_MAX_TAGS (Nick Piggin's idea). Tag parameters are changed to unsigned, and some comments are updated. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 03:08:05 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] buglet in radix_tree_tag_set The comment states: 'Setting a tag on a not-present item is a BUG.' Hence if 'index' is larger than the maxindex; the item _cannot_ be presen; it should also be a BUG. Also, this allows the following statement (assume a fresh tree): radix_tree_tag_set(root, 16, 1); to fail silently, but when preceded by: radix_tree_insert(root, 32, item); it would BUG, because the height has been extended by the insert. In neither case was 16 present. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:25 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix tree: early termination of tag clearing Correctly determine the tags to be cleared in radix_tree_delete() so we don't keep moving up the tree clearing tags that we don't need to. For example, if a tag is simply not set in the deleted item, nor anywhere up the tree, radix_tree_delete() would attempt to clear it up the entire height of the tree. Also, tag_set() was made conditional so as not to dirty too many cachelines high up in the radix tree. Instead, put this logic into radix_tree_tag_set(). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:01:41 -08:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree documentation cleanups Documentation changes to help radix tree users avoid overrunning the tags array. RADIX_TREE_TAGS moves to linux/radix-tree.h and is now known as RADIX_TREE_MAX_TAGS (Nick Piggin's idea). Tag parameters are changed to unsigned, and some comments are updated. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 03:08:05 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree documentation cleanups Documentation changes to help radix tree users avoid overrunning the tags array. RADIX_TREE_TAGS moves to linux/radix-tree.h and is now known as RADIX_TREE_MAX_TAGS (Nick Piggin's idea). Tag parameters are changed to unsigned, and some comments are updated. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 03:08:05 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
fix the max path calculation in radix-tree.c A while back, Nick Piggin introduced a patch to reduce the node memory usage for small files (commit cfd9b7df4abd3257c9e381b0e445817b26a51c0c): -#define RADIX_TREE_MAP_SHIFT 6 +#define RADIX_TREE_MAP_SHIFT (CONFIG_BASE_SMALL ? 4 : 6) Unfortunately, he didn't take into account the fact that the calculation of the maximum path was based on an assumption of having to round up: #define RADIX_TREE_MAX_PATH (RADIX_TREE_INDEX_BITS/RADIX_TREE_MAP_SHIFT + 2) So, if CONFIG_BASE_SMALL is set, you will end up with a RADIX_TREE_MAX_PATH that is one greater than necessary. The practical upshot of this is just a bit of wasted memory (one long in the height_to_maxindex array, an extra pre-allocated radix tree node per cpu, and extra stack usage in a couple of functions), but it seems worth getting right. It's also worth noting that I never build with CONFIG_BASE_SMALL. What I did to test this was duplicate the code in a small user-space program and check the results of the calculations for max path and the contents of the height_to_maxindex array. Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:49 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
[PATCH] radix tree: early termination of tag clearing Correctly determine the tags to be cleared in radix_tree_delete() so we don't keep moving up the tree clearing tags that we don't need to. For example, if a tag is simply not set in the deleted item, nor anywhere up the tree, radix_tree_delete() would attempt to clear it up the entire height of the tree. Also, tag_set() was made conditional so as not to dirty too many cachelines high up in the radix tree. Instead, put this logic into radix_tree_tag_set(). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:01:41 -08:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
[PATCH] radix tree: code consolidation Introduce helper any_tag_set() rather than repeat the same code sequence 4 times. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:01:40 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix_tag_get(): differentiate between no present node and tag unset cases Simple patch to radix_tree_tag_get() to return different values for non present node and tag unset. The function is not used by any in-kernel callers (yet), but this information is definitely useful. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:48 -07:00
[PATCH] radix-tree documentation cleanups Documentation changes to help radix tree users avoid overrunning the tags array. RADIX_TREE_TAGS moves to linux/radix-tree.h and is now known as RADIX_TREE_MAX_TAGS (Nick Piggin's idea). Tag parameters are changed to unsigned, and some comments are updated. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 03:08:05 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix_tag_get(): differentiate between no present node and tag unset cases Simple patch to radix_tree_tag_get() to return different values for non present node and tag unset. The function is not used by any in-kernel callers (yet), but this information is definitely useful. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:48 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree documentation cleanups Documentation changes to help radix tree users avoid overrunning the tags array. RADIX_TREE_TAGS moves to linux/radix-tree.h and is now known as RADIX_TREE_MAX_TAGS (Nick Piggin's idea). Tag parameters are changed to unsigned, and some comments are updated. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 03:08:05 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radixtree: normalize radix_tree_tag_get() return value In radix_tree_tag_get(), return normalized value of 0/1, as indicated by its comment. Signed-off-by: Wu Fengguang <wfg@mail.ustc.edu.cn> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25 05:48:14 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radixtree: introduce radix_tree_next_hole() Introduce radix_tree_next_hole(root, index, max_scan) to scan radix tree for the first hole. It will be used in interleaved readahead. The implementation is dumb and obviously correct. It can help debug(and document) the possible smart one in future. Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:33 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: add gang_lookup_slot, gang_lookup_slot_tag Introduce gang_lookup_slot() and gang_lookup_slot_tag() functions, which are used by lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 19:45:29 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
radix-tree: add gang_lookup_slot, gang_lookup_slot_tag Introduce gang_lookup_slot() and gang_lookup_slot_tag() functions, which are used by lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 19:45:29 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: add gang_lookup_slot, gang_lookup_slot_tag Introduce gang_lookup_slot() and gang_lookup_slot_tag() functions, which are used by lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 19:45:29 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: add gang_lookup_slot, gang_lookup_slot_tag Introduce gang_lookup_slot() and gang_lookup_slot_tag() functions, which are used by lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 19:45:29 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: add gang_lookup_slot, gang_lookup_slot_tag Introduce gang_lookup_slot() and gang_lookup_slot_tag() functions, which are used by lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 19:45:29 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: add gang_lookup_slot, gang_lookup_slot_tag Introduce gang_lookup_slot() and gang_lookup_slot_tag() functions, which are used by lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 19:45:29 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: add gang_lookup_slot, gang_lookup_slot_tag Introduce gang_lookup_slot() and gang_lookup_slot_tag() functions, which are used by lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 19:45:29 -07:00
[PATCH] radix-tree documentation cleanups Documentation changes to help radix tree users avoid overrunning the tags array. RADIX_TREE_TAGS moves to linux/radix-tree.h and is now known as RADIX_TREE_MAX_TAGS (Nick Piggin's idea). Tag parameters are changed to unsigned, and some comments are updated. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 03:08:05 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
radix-tree: add gang_lookup_slot, gang_lookup_slot_tag Introduce gang_lookup_slot() and gang_lookup_slot_tag() functions, which are used by lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 19:45:29 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree documentation cleanups Documentation changes to help radix tree users avoid overrunning the tags array. RADIX_TREE_TAGS moves to linux/radix-tree.h and is now known as RADIX_TREE_MAX_TAGS (Nick Piggin's idea). Tag parameters are changed to unsigned, and some comments are updated. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 03:08:05 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree documentation cleanups Documentation changes to help radix tree users avoid overrunning the tags array. RADIX_TREE_TAGS moves to linux/radix-tree.h and is now known as RADIX_TREE_MAX_TAGS (Nick Piggin's idea). Tag parameters are changed to unsigned, and some comments are updated. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 03:08:05 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: add gang_lookup_slot, gang_lookup_slot_tag Introduce gang_lookup_slot() and gang_lookup_slot_tag() functions, which are used by lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 19:45:29 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: add gang_lookup_slot, gang_lookup_slot_tag Introduce gang_lookup_slot() and gang_lookup_slot_tag() functions, which are used by lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 19:45:29 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
radix-tree: add gang_lookup_slot, gang_lookup_slot_tag Introduce gang_lookup_slot() and gang_lookup_slot_tag() functions, which are used by lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 19:45:29 -07:00
[PATCH] radix-tree: reduce tree height upon partial truncation Shrink the height of a radix tree when it is partially truncated - we only do shrinkage of full truncation at present. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:01:41 -08:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: reduce tree height upon partial truncation Shrink the height of a radix tree when it is partially truncated - we only do shrinkage of full truncation at present. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:01:41 -08:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
[PATCH] radix-tree: reduce tree height upon partial truncation Shrink the height of a radix tree when it is partially truncated - we only do shrinkage of full truncation at present. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:01:41 -08:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
[PATCH] radix-tree: reduce tree height upon partial truncation Shrink the height of a radix tree when it is partially truncated - we only do shrinkage of full truncation at present. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:01:41 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
fix the max path calculation in radix-tree.c A while back, Nick Piggin introduced a patch to reduce the node memory usage for small files (commit cfd9b7df4abd3257c9e381b0e445817b26a51c0c): -#define RADIX_TREE_MAP_SHIFT 6 +#define RADIX_TREE_MAP_SHIFT (CONFIG_BASE_SMALL ? 4 : 6) Unfortunately, he didn't take into account the fact that the calculation of the maximum path was based on an assumption of having to round up: #define RADIX_TREE_MAX_PATH (RADIX_TREE_INDEX_BITS/RADIX_TREE_MAP_SHIFT + 2) So, if CONFIG_BASE_SMALL is set, you will end up with a RADIX_TREE_MAX_PATH that is one greater than necessary. The practical upshot of this is just a bit of wasted memory (one long in the height_to_maxindex array, an extra pre-allocated radix tree node per cpu, and extra stack usage in a couple of functions), but it seems worth getting right. It's also worth noting that I never build with CONFIG_BASE_SMALL. What I did to test this was duplicate the code in a small user-space program and check the results of the calculations for max path and the contents of the height_to_maxindex array. Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:49 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix tree: early termination of tag clearing Correctly determine the tags to be cleared in radix_tree_delete() so we don't keep moving up the tree clearing tags that we don't need to. For example, if a tag is simply not set in the deleted item, nor anywhere up the tree, radix_tree_delete() would attempt to clear it up the entire height of the tree. Also, tag_set() was made conditional so as not to dirty too many cachelines high up in the radix tree. Instead, put this logic into radix_tree_tag_set(). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:01:41 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix tree: early termination of tag clearing Correctly determine the tags to be cleared in radix_tree_delete() so we don't keep moving up the tree clearing tags that we don't need to. For example, if a tag is simply not set in the deleted item, nor anywhere up the tree, radix_tree_delete() would attempt to clear it up the entire height of the tree. Also, tag_set() was made conditional so as not to dirty too many cachelines high up in the radix tree. Instead, put this logic into radix_tree_tag_set(). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:01:41 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix tree: early termination of tag clearing Correctly determine the tags to be cleared in radix_tree_delete() so we don't keep moving up the tree clearing tags that we don't need to. For example, if a tag is simply not set in the deleted item, nor anywhere up the tree, radix_tree_delete() would attempt to clear it up the entire height of the tree. Also, tag_set() was made conditional so as not to dirty too many cachelines high up in the radix tree. Instead, put this logic into radix_tree_tag_set(). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:01:41 -08:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree documentation cleanups Documentation changes to help radix tree users avoid overrunning the tags array. RADIX_TREE_TAGS moves to linux/radix-tree.h and is now known as RADIX_TREE_MAX_TAGS (Nick Piggin's idea). Tag parameters are changed to unsigned, and some comments are updated. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 03:08:05 -08:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
[PATCH] radix tree: early termination of tag clearing Correctly determine the tags to be cleared in radix_tree_delete() so we don't keep moving up the tree clearing tags that we don't need to. For example, if a tag is simply not set in the deleted item, nor anywhere up the tree, radix_tree_delete() would attempt to clear it up the entire height of the tree. Also, tag_set() was made conditional so as not to dirty too many cachelines high up in the radix tree. Instead, put this logic into radix_tree_tag_set(). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:01:41 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
[PATCH] radix-tree: reduce tree height upon partial truncation Shrink the height of a radix tree when it is partially truncated - we only do shrinkage of full truncation at present. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:01:41 -08:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
[PATCH] radix-tree: reduce tree height upon partial truncation Shrink the height of a radix tree when it is partially truncated - we only do shrinkage of full truncation at present. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:01:41 -08:00
radix-tree: use indirect bit Rather than sign direct radix-tree pointers with a special bit, sign the indirect one that hangs off the root. This means that, given a lookup_slot operation, the invalid result will be differentiated from the valid (previously, valid results could have the bit either set or clear). This does not affect slot lookups which occur under lock -- they can never return an invalid result. Is needed in future for lockless pagecache. Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:24:42 -07:00
[PATCH] radix-tree: reduce tree height upon partial truncation Shrink the height of a radix tree when it is partially truncated - we only do shrinkage of full truncation at present. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:01:41 -08:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
[PATCH] radix-tree: reduce tree height upon partial truncation Shrink the height of a radix tree when it is partially truncated - we only do shrinkage of full truncation at present. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 01:01:41 -08:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
[PATCH] radix-tree: Remove unnecessary indirections and clean up code - There is frequent use of indirections in the radix code. This patch removes those indirections, makes the code more readable and allows the compilers to generate better code. - Removing indirections allows the removal of several casts. - Removing indirections allows the reduction of the radix_tree_path size from 3 to 2 words. - Use pathp-> consistently. - Remove unnecessary tmp variable in radix_tree_insert - Separate the upper layer processing from the lowest layer in __lookup() in order to make it easier to understand what is going on and allow compilers to generate better code for the loop. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-06 15:16:46 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
[PATCH] radix-tree: RCU lockless readside Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-06 20:33:44 -08:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree documentation cleanups Documentation changes to help radix tree users avoid overrunning the tags array. RADIX_TREE_TAGS moves to linux/radix-tree.h and is now known as RADIX_TREE_MAX_TAGS (Nick Piggin's idea). Tag parameters are changed to unsigned, and some comments are updated. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 03:08:05 -08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
[PATCH] radix-tree: direct data The ability to have height 0 radix trees (a direct pointer to the data item rather than going through a full node->slot) quietly disappeared with old-2.6-bkcvs commit ffee171812d51652f9ba284302d9e5c5cc14bdfd. On 64-bit machines this causes nearly 600 bytes to be used for every <= 4K file in pagecache. Re-introduce this feature, root tags stored in spare ->gfp_mask bits. Simplify radix_tree_delete's complex tag clearing arrangement (which would become even more complex) by just falling back to tag clearing functions (the pagecache radix-tree never uses this path anyway, so the icache savings will mean it's actually a speedup). On my 4GB G5, this saves 8MB RAM per kernel kernel source+object tree in pagecache. Pagecache lookup, insertion, and removal speed for small files will also be improved. This makes RCU radix tree harder, but it's worth it. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 02:03:22 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
SL*B: drop kmem cache argument from constructor Kmem cache passed to constructor is only needed for constructors that are themselves multiplexeres. Nobody uses this "feature", nor does anybody uses passed kmem cache in non-trivial way, so pass only pointer to object. Non-trivial places are: arch/powerpc/mm/init_64.c arch/powerpc/mm/hugetlbpage.c This is flag day, yes. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Christoph Lameter <cl@linux-foundation.org> Cc: Jon Tollefson <kniht@linux.vnet.ibm.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Matt Mackall <mpm@selenic.com> [akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c] [akpm@linux-foundation.org: fix mm/slab.c] [akpm@linux-foundation.org: fix ubifs] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 19:45:34 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
avoid negative (and full-width) shifts in radix-tree.c Negative shifts are not allowed in C (the result is undefined). Same thing with full-width shifts. It works on most platforms but not on the VAX with gcc 4.0.1 (it results in an "operand reserved" fault). Shifting by more than the width of the value on the left is also not allowed. I think the extra '>> 1' tacked on at the end in the original code was an attempt to work around that. Getting rid of that is an extra feature of this patch. Here's the chapter and verse, taken from the final draft of the C99 standard ("6.5.7 Bitwise shift operators", paragraph 3): "The integer promotions are performed on each of the operands. The type of the result is that of the promoted left operand. If the value of the right operand is negative or is greater than or equal to the width of the promoted left operand, the behavior is undefined." Thank you to Jan-Benedict Glaw, Christoph Hellwig, Maciej Rozycki, Pekka Enberg, Andreas Schwab, and Christoph Lameter for review. Special thanks to Andreas for spotting that my fix only removed half the undefined behaviour. Signed-off-by: Peter Lund <firefly@vax64.dk> Christoph Lameter <clameter@sgi.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Andreas Schwab <schwab@suse.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: WU Fengguang <wfg@mail.ustc.edu.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 23:29:35 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
Add suspend-related notifications for CPU hotplug Since nonboot CPUs are now disabled after tasks and devices have been frozen and the CPU hotplug infrastructure is used for this purpose, we need special CPU hotplug notifications that will help the CPU-hotplug-aware subsystems distinguish normal CPU hotplug events from CPU hotplug events related to a system-wide suspend or resume operation in progress. This patch introduces such notifications and causes them to be used during suspend and resume transitions. It also changes all of the CPU-hotplug-aware subsystems to take these notifications into consideration (for now they are handled in the same way as the corresponding "normal" ones). [oleg@tv-sign.ru: cleanups] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 02:35:10 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00
Remove set_migrateflags() Migrate flags must be set on slab creation as agreed upon when the antifrag logic was reviewed. Otherwise some slabs of a slabcache will end up in the unmovable and others in the reclaimable section depending on which flag was active when a new slab page was allocated. This likely slid in somehow when antifrag was merged. Remove it. The buffer_heads are always allocated with __GFP_RECLAIMABLE because the SLAB_RECLAIM_ACCOUNT option is set. The set_migrateflags() never had any effect there. Radix tree allocations are not directly reclaimable but they are allocated with __GFP_RECLAIMABLE set on each allocation. We now set SLAB_RECLAIM_ACCOUNT on radix tree slab creation making sure that radix tree slabs are consistently placed in the reclaimable section. Radix tree slabs will also be accounted as such. There is then no user left of set_migratepages. So remove it. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 02:12:05 -07:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 15:20:36 -07:00