linux/mm/vmalloc.c

825 lines
19 KiB

[PATCH] mm: init_mm without ptlock First step in pushing down the page_table_lock. init_mm.page_table_lock has been used throughout the architectures (usually for ioremap): not to serialize kernel address space allocation (that's usually vmlist_lock), but because pud_alloc,pmd_alloc,pte_alloc_kernel expect caller holds it. Reverse that: don't lock or unlock init_mm.page_table_lock in any of the architectures; instead rely on pud_alloc,pmd_alloc,pte_alloc_kernel to take and drop it when allocating a new one, to check lest a racing task already did. Similarly no page_table_lock in vmalloc's map_vm_area. Some temporary ugliness in __pud_alloc and __pmd_alloc: since they also handle user mms, which are converted only by a later patch, for now they have to lock differently according to whether or not it's init_mm. If sources get muddled, there's a danger that an arch source taking init_mm.page_table_lock will be mixed with common source also taking it (or neither take it). So break the rules and make another change, which should break the build for such a mismatch: remove the redundant mm arg from pte_alloc_kernel (ppc64 scrapped its distinct ioremap_mm in 2.6.13). Exceptions: arm26 used pte_alloc_kernel on user mm, now pte_alloc_map; ia64 used pte_alloc_map on init_mm, now pte_alloc_kernel; parisc had bad args to pmd_alloc and pte_alloc_kernel in unused USE_HPPA_IOREMAP code; ppc64 map_io_page forgot to unlock on failure; ppc mmu_mapin_ram and ppc64 im_free took page_table_lock for no good reason. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29 18:16:21 -07:00
Categorize GFP flags The function of GFP_LEVEL_MASK seems to be unclear. In order to clear up the mystery we get rid of it and replace GFP_LEVEL_MASK with 3 sets of GFP flags: GFP_RECLAIM_MASK Flags used to control page allocator reclaim behavior. GFP_CONSTRAINT_MASK Flags used to limit where allocations can occur. GFP_SLAB_BUG_MASK Flags that the slab allocator BUG()s on. These replace the uses of GFP_LEVEL mask in the slab allocators and in vmalloc.c. The use of the flags not included in these sets may occur as a result of a slab allocation standing in for a page allocation when constructing scatter gather lists. Extraneous flags are cleared and not passed through to the page allocator. __GFP_MOVABLE/RECLAIMABLE, __GFP_COLD and __GFP_COMP will now be ignored if passed to a slab allocator. Change the allocation of allocator meta data in SLAB and vmalloc to not pass through flags listed in GFP_CONSTRAINT_MASK. SLAB already removes the __GFP_THISNODE flag for such allocations. Generalize that to also cover vmalloc. The use of GFP_CONSTRAINT_MASK also includes __GFP_HARDWALL. The impact of allocator metadata placement on access latency to the cachelines of the object itself is minimal since metadata is only referenced on alloc and free. The attempt is still made to place the meta data optimally but we consistently allow fallback both in SLAB and vmalloc (SLUB does not need to allocate metadata like that). Allocator metadata may serve multiple in kernel users and thus should not be subject to the limitations arising from a single allocation context. [akpm@linux-foundation.org: fix fallback_alloc()] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:25:41 -07:00
Categorize GFP flags The function of GFP_LEVEL_MASK seems to be unclear. In order to clear up the mystery we get rid of it and replace GFP_LEVEL_MASK with 3 sets of GFP flags: GFP_RECLAIM_MASK Flags used to control page allocator reclaim behavior. GFP_CONSTRAINT_MASK Flags used to limit where allocations can occur. GFP_SLAB_BUG_MASK Flags that the slab allocator BUG()s on. These replace the uses of GFP_LEVEL mask in the slab allocators and in vmalloc.c. The use of the flags not included in these sets may occur as a result of a slab allocation standing in for a page allocation when constructing scatter gather lists. Extraneous flags are cleared and not passed through to the page allocator. __GFP_MOVABLE/RECLAIMABLE, __GFP_COLD and __GFP_COMP will now be ignored if passed to a slab allocator. Change the allocation of allocator meta data in SLAB and vmalloc to not pass through flags listed in GFP_CONSTRAINT_MASK. SLAB already removes the __GFP_THISNODE flag for such allocations. Generalize that to also cover vmalloc. The use of GFP_CONSTRAINT_MASK also includes __GFP_HARDWALL. The impact of allocator metadata placement on access latency to the cachelines of the object itself is minimal since metadata is only referenced on alloc and free. The attempt is still made to place the meta data optimally but we consistently allow fallback both in SLAB and vmalloc (SLUB does not need to allocate metadata like that). Allocator metadata may serve multiple in kernel users and thus should not be subject to the limitations arising from a single allocation context. [akpm@linux-foundation.org: fix fallback_alloc()] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 01:25:41 -07:00
[PATCH] DocBook: changes and extensions to the kernel documentation I have recompiled Linux kernel 2.6.11.5 documentation for me and our university students again. The documentation could be extended for more sources which are equipped by structured comments for recent 2.6 kernels. I have tried to proceed with that task. I have done that more times from 2.6.0 time and it gets boring to do same changes again and again. Linux kernel compiles after changes for i386 and ARM targets. I have added references to some more files into kernel-api book, I have added some section names as well. So please, check that changes do not break something and that categories are not too much skewed. I have changed kernel-doc to accept "fastcall" and "asmlinkage" words reserved by kernel convention. Most of the other changes are modifications in the comments to make kernel-doc happy, accept some parameters description and do not bail out on errors. Changed <pid> to @pid in the description, moved some #ifdef before comments to correct function to comments bindings, etc. You can see result of the modified documentation build at http://cmp.felk.cvut.cz/~pisa/linux/lkdb-2.6.11.tar.gz Some more sources are ready to be included into kernel-doc generated documentation. Sources has been added into kernel-api for now. Some more section names added and probably some more chaos introduced as result of quick cleanup work. Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz> Signed-off-by: Martin Waitz <tali@admingilde.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 08:59:25 -07:00