Commit graph

158,501 commits

Author SHA1 Message Date
Shakeel Butt
0ccaf421d6 memcg: allocate v1 event percpu only on v1 deployment
Currently memcg->events_percpu gets allocated on v2 deployments.  Let's
move the allocation to v1 only codebase.  This is not needed in v2.

Link: https://lkml.kernel.org/r/20240815050453.1298138-7-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: T.J. Mercier <tjmercier@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:20 -07:00
Shakeel Butt
5d383b69a0 memcg: move v1 only percpu stats in separate struct
Patch series "memcg: further decouple v1 code from v2".

Some of the v1 code is still in v2 code base due to v1 fields in the
struct memcg_vmstats_percpu.  This field decouples those fileds from v2
struct and move all the related code into v1 only code base.


This patch (of 7):

At the moment struct memcg_vmstats_percpu contains two v1 only fields
which consumes memory even when CONFIG_MEMCG_V1 is not enabled.  In
addition there are v1 only functions accessing them and are in the main
memcontrol source file and can not be moved to v1 only source file due to
these fields.  Let's move these fields into their own struct.  Later
patches will move the functions accessing them to v1 source file and only
allocate these fields when CONFIG_MEMCG_V1 is enabled.

Link: https://lkml.kernel.org/r/20240815050453.1298138-1-shakeel.butt@linux.dev
Link: https://lkml.kernel.org/r/20240815050453.1298138-2-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: T.J. Mercier <tjmercier@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:18 -07:00
Sidhartha Kumar
bd164d81a7 maple_tree: introduce store_type enum
Patch series "Introduce a store type enum for the Maple tree", v4.

================================ OVERVIEW ================================

This series implements two work items[3]: "aligning mas_store_gfp() with
mas_preallocate()" and "enum for store type".

mas_store_gfp() is modified to preallocate nodes.  This simplies many of
the write helper functions by allowing them to use mas_store_gfp() rather
than open coding node allocation and error handling.

The enum defines the following store types:

enum store_type {
    wr_invalid,
    wr_new_root,
    wr_store_root,
    wr_exact_fit,
    wr_spanning_store,
    wr_split_store,
    wr_rebalance,
    wr_append,
    wr_node_store,
    wr_slot_store,
};

In the current maple tree code, a walk down the tree is done in
mas_preallocate() to determine the number of nodes needed for this write. 
After node allocation, mas_wr_store_entry() will perform another walk to
determine which write helper function to use to complete the write.

Rather than performing the second walk, we can store the type of write in
the maple write state during node allocation and read this field to
complete the write.

Patches 1-16 implement this store type feature.
Patch 17 is a cleanup patch to change functions that have unused return
types to be void.

================================ RESULTS =================================

Phoronix t-test-1 (Seconds < Lower Is Better)
    v6.10-rc6
        Threads: 1
            33.15

        Threads: 2
            10.81

    v6.10-rc6 + this series
            Threads: 1
            32.69

        Threads: 2
            10.45

Stress-ng mmap
                    6.10_base  store_type_v4
Duration User        2744.65     2769.40
Duration System     10862.69    10817.59
Duration Elapsed     1477.58     1478.35



================================ TESTING =================================

Testing was done with the maple tree test suite.  A new test case is also
added to validate the order in which we test for and assign the store
type.

[1]: https://lore.kernel.org/linux-mm/80926b22-a8d2-9992-eb5e-27e2c99cf460@google.com/T/#m81044feb66765265f8ca7f21e4b4b3725b18780a
[2]: https://lore.kernel.org/linux-mm/80926b22-a8d2-9992-eb5e-27e2c99cf460@google.com/T/#mb36c6526486638e82518c0f37a428fb279c84d8a
[3]: https://lists.infradead.org/pipermail/maple-tree/2023-December/003098.html


This patch (of 17):

Add a store_type enum that is stored in ma_state.  This will be used to
keep track of partial walks of the tree so that subsequent walks can pick
up where a previous walk left off.

Link: https://lkml.kernel.org/r/20240814161944.55347-1-sidhartha.kumar@oracle.com
Link: https://lkml.kernel.org/r/20240814161944.55347-2-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:14 -07:00
Muchun Song
02f4bbefca mm: kmem: add lockdep assertion to obj_cgroup_memcg
obj_cgroup_memcg() is supposed to safe to prevent the returned memory
cgroup from being freed only when the caller is holding the rcu read lock
or objcg_lock or cgroup_mutex.  It is very easy to ignore thoes conditions
when users call some upper APIs which call obj_cgroup_memcg() internally
like mem_cgroup_from_slab_obj() (See the link below).  So it is better to
add lockdep assertion to obj_cgroup_memcg() to find those issues ASAP.

Because there is no user of obj_cgroup_memcg() holding objcg_lock to make
the returned memory cgroup safe, do not add objcg_lock assertion (We
should export objcg_lock if we really want to do).  Additionally, this is
some internal implementation detail of memcg and should not be accessible
outside memcg code.

Some users like __mem_cgroup_uncharge() do not care the lifetime of the
returned memory cgroup, which just want to know if the folio is charged to
a memory cgroup, therefore, they do not need to hold the needed locks.  In
which case, introduce a new helper folio_memcg_charged() to do this. 
Compare it to folio_memcg(), it could eliminate a memory access of
objcg->memcg for kmem, actually, a really small gain.

[songmuchun@bytedance.com: fix split_page_memcg()]
  Link: https://lkml.kernel.org/r/20240819080415.44964-1-songmuchun@bytedance.com
Link: https://lore.kernel.org/all/20240718083607.42068-1-songmuchun@bytedance.com/
Link: https://lkml.kernel.org/r/20240814093415.17634-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:14 -07:00
Linus Torvalds
497258dfaf mm: remove legacy install_special_mapping() code
All relevant architectures had already been converted to the new interface
(which just has an underscore in front of the name - not very imaginative
naming), this just force-converts the stragglers.

The modern interface is almost identical to the old one, except instead of
the page pointer it takes a "struct vm_special_mapping" that describes the
mapping (and contains the page pointer as one member), and it returns the
resulting 'vma' instead of just the error code.

Getting rid of the old interface also gets rid of some special casing,
which had caused problems with the mremap extensions to "struct
vm_special_mapping".

[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/CAHk-=whvR+z=0=0gzgdfUiK70JTa-=+9vxD-4T=3BagXR6dciA@mail.gmail.comTested-by: Rob Landley <rob@landley.net> # arch/sh/
Link: https://lore.kernel.org/all/20240819195120.GA1113263@thelio-3990X/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Jeff Xu <jeffxu@google.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Landley <rob@landley.net>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:13 -07:00
Michael Ellerman
40b88644dd mm: remove arch_unmap()
Now that powerpc no longer uses arch_unmap() to handle VDSO unmapping,
there are no meaningful implementions left.  Drop support for it entirely,
and update comments which refer to it.

Link: https://lkml.kernel.org/r/20240812082605.743814-3-mpe@ellerman.id.au
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Jeff Xu <jeffxu@google.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:13 -07:00
Michael Ellerman
223febc6e5 mm: add optional close() to struct vm_special_mapping
Add an optional close() callback to struct vm_special_mapping.  It will be
used, by powerpc at least, to handle unmapping of the VDSO.

Although support for unmapping the VDSO was initially added for CRIU[1],
it is not desirable to guard that support behind
CONFIG_CHECKPOINT_RESTORE.

There are other known users of unmapping the VDSO which are not related to
CRIU, eg.  Valgrind [2] and void-ship [3].

The powerpc arch_unmap() hook has been in place for ~9 years, with no
ifdef, so there may be other unknown users that have come to rely on
unmapping the VDSO.  Even if the code was behind an ifdef, major distros
enable CHECKPOINT_RESTORE so users may not realise unmapping the VDSO
depends on that configuration option.

It's also undesirable to have such core mm behaviour behind a relatively
obscure CONFIG option.

Longer term the unmap behaviour should be standardised across
architectures, however that is complicated by the fact the VDSO pointer is
stored differently across architectures.  There was a previous attempt to
unify that handling [4], which could be revived.

See [5] for further discussion.

[1]: commit 83d3f0e90c ("powerpc/mm: tracking vDSO remap")
[2]: https://sourceware.org/git/?p=valgrind.git;a=commit;h=3a004915a2cbdcdebafc1612427576bf3321eef5
[3]: https://github.com/insanitybit/void-ship
[4]: https://lore.kernel.org/lkml/20210611180242.711399-17-dima@arista.com/
[5]: https://lore.kernel.org/linuxppc-dev/shiq5v3jrmyi6ncwke7wgl76ojysgbhrchsk32q4lbx2hadqqc@kzyy2igem256

Link: https://lkml.kernel.org/r/20240812082605.743814-1-mpe@ellerman.id.au
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Jeff Xu <jeffxu@google.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:12 -07:00
Takaya Saeki
b6273b55d8 filemap: add trace events for get_pages, map_pages, and fault
To allow precise tracking of page caches accessed, add new tracepoints
that trigger when a process actually accesses them.

The ureadahead program used by ChromeOS traces the disk access of programs
as they start up at boot up.  It uses mincore(2) or the
'mm_filemap_add_to_page_cache' trace event to accomplish this.  It stores
this information in a "pack" file and on subsequent boots, it will read
the pack file and call readahead(2) on the information so that disk
storage can be loaded into RAM before the applications actually need it.

A problem we see is that due to the kernel's readahead algorithm that can
aggressively pull in more data than needed (to try and accomplish the same
goal) and this data is also recorded.  The end result is that the pack
file contains a lot of pages on disk that are never actually used. 
Calling readahead(2) on these unused pages can slow down the system boot
up times.

To solve this, add 3 new trace events, get_pages, map_pages, and fault. 
These will be used to trace the pages are not only pulled in from disk,
but are actually used by the application.  Only those pages will be stored
in the pack file, and this helps out the performance of boot up.

With the combination of these 3 new trace events and
mm_filemap_add_to_page_cache, we observed a reduction in the pack file by
7.3% - 20% on ChromeOS varying by device.

Link: https://lkml.kernel.org/r/20240813100312.3930505-1-takayas@chromium.org
Signed-off-by: Takaya Saeki <takayas@chromium.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Junichi Uekawa <uekawa@chromium.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:10 -07:00
Peter Xu
cb0f01beb1 mm/mprotect: fix dax pud handlings
This is only relevant to the two archs that support PUD dax, aka, x86_64
and ppc64.  PUD THPs do not yet exist elsewhere, and hugetlb PUDs do not
count in this case.

DAX have had PUD mappings for years, but change protection path never
worked.  When the path is triggered in any form (a simple test program
would be: call mprotect() on a 1G dev_dax mapping), the kernel will report
"bad pud".  This patch should fix that.

The new change_huge_pud() tries to keep everything simple.  For example,
it doesn't optimize write bit as that will need even more PUD helpers. 
It's not too bad anyway to have one more write fault in the worst case
once for 1G range; may be a bigger thing for each PAGE_SIZE, though. 
Neither does it support userfault-wp bits, as there isn't such PUD
mappings that is supported; file mappings always need a split there.

The same to TLB shootdown: the pmd path (which was for x86 only) has the
trick of using _ad() version of pmdp_invalidate*() which can avoid one
redundant TLB, but let's also leave that for later.  Again, the larger the
mapping, the smaller of such effect.

There's some difference on handling "retry" for change_huge_pud() (where
it can return 0): it isn't like change_huge_pmd(), as the pmd version is
safe with all conditions handled in change_pte_range() later, thanks to
Hugh's new pte_offset_map_lock().  In short, change_pte_range() is simply
smarter.  For that, change_pud_range() will need proper retry if it races
with something else when a huge PUD changed from under us.

The last thing to mention is currently the PUD path ignores the huge pte
numa counter (NUMA_HUGE_PTE_UPDATES), not only because DAX is not
applicable to NUMA, but also that it's ambiguous on its own to decide how
to account pud in this case.  In one earlier version of this patchset I
proposed to remove the counter as it doesn't even look right to do the
accounting as of now [1], but then a further discussion suggests we can
leave that for later, as that doesn't block this series if we choose to
ignore that counter.  That's what this patch does, by ignoring it.

When at it, touch up the comment in pgtable_split_needed() to make it
generic to either pmd or pud file THPs.

[1] https://lore.kernel.org/all/20240715192142.3241557-3-peterx@redhat.com/
[2] https://lore.kernel.org/r/added2d0-b8be-4108-82ca-1367a388d0b1@redhat.com

Link: https://lkml.kernel.org/r/20240812181225.1360970-8-peterx@redhat.com
Fixes: a00cc7d9dd ("mm, x86: add support for PUD-sized transparent hugepages")
Fixes: 27af67f356 ("powerpc/book3s64/mm: enable transparent pud hugepage")
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:10 -07:00
Peter Xu
1c399e74a9 mm/x86: implement arch_check_zapped_pud()
Introduce arch_check_zapped_pud() to sanity check shadow stack on PUD
zaps.  It has the same logic as the PMD helper.

One thing to mention is, it might be a good idea to use page_table_check
in the future for trapping wrong setups of shadow stack pgtable entries
[1].  That is left for the future as a separate effort.

[1] https://lore.kernel.org/all/59d518698f664e07c036a5098833d7b56b953305.camel@intel.com

Link: https://lkml.kernel.org/r/20240812181225.1360970-6-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:09 -07:00
Kirill A. Shutemov
5adfeaecc4 mm: rework accept memory helpers
Make accept_memory() and range_contains_unaccepted_memory() take 'start'
and 'size' arguments instead of 'start' and 'end'.

Remove accept_page(), replacing it with direct calls to accept_memory(). 
The accept_page() name is going to be used for a different function.

Link: https://lkml.kernel.org/r/20240809114854.3745464-6-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:07 -07:00
Kirill A. Shutemov
310183de7b mm: introduce PageUnaccepted() page type
The new page type allows physical memory scanners to detect unaccepted
memory and handle it accordingly.

The page type is serialized with zone lock.

Link: https://lkml.kernel.org/r/20240809114854.3745464-5-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:06 -07:00
Matthew Wilcox (Oracle)
09022bc196 mm: remove PG_error
The PG_error bit is now unused; delete it and free up a bit in
page->flags.

Link: https://lkml.kernel.org/r/20240807193528.1865100-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:05 -07:00
Jianhui Zhou
47baed6a13 percpu: remove pcpu_alloc_size()
pcpu_alloc_size() was added in 7ac5c53e00 "mm/percpu.c: introduce
pcpu_alloc_size()", which is used to get the allocated memory size in bpf.
However, pcpu_alloc_size() is no longer used in "bpf: Use c->unit_size to
select target cache during free" because its actuall allocated memory size
may change at runtime due to its slab merging mechanism.  Therefore,
pcpu_alloc_size() can be removed.

Link: https://lkml.kernel.org/r/tencent_AD5C50E8D78C07A3CE539BD5F6BF39706507@qq.com
Signed-off-by: Jianhui Zhou <912460177@qq.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: JonasZhou <JonasZhou@zhaoxin.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:04 -07:00
Marco Elver
cc0a0f9855 kfence: introduce burst mode
Introduce burst mode, which can be configured with kfence.burst=$count,
where the burst count denotes the additional successive slab allocations
to be allocated through KFENCE for each sample interval.

The idea is that this can give developers an additional knob to make
KFENCE more aggressive when debugging specific issues of systems where
either rebooting or recompiling the kernel with KASAN is not possible.

Experiment: To assess the effectiveness of the new option, we randomly
picked a recent out-of-bounds [1] and use-after-free bug [2], each with a
reproducer provided by syzbot, that initially detected these bugs with
KASAN.  We then tried to reproduce the bugs with KFENCE below.

[1] Fixed by: 7c55b78818 ("jfs: xattr: fix buffer overflow for invalid xattr")
    https://syzkaller.appspot.com/bug?id=9d1b59d4718239da6f6069d3891863c25f9f24a2
[2] Fixed by: f8ad00f3fb ("l2tp: fix possible UAF when cleaning up tunnels")
    https://syzkaller.appspot.com/bug?id=4f34adc84f4a3b080187c390eeef60611fd450e1

The following KFENCE configs were compared. A pool size of 1023 objects
was used for all configurations.

	Baseline
		kfence.sample_interval=100
		kfence.skip_covered_thresh=75
		kfence.burst=0

	Aggressive
		kfence.sample_interval=1
		kfence.skip_covered_thresh=10
		kfence.burst=0

	AggressiveBurst
		kfence.sample_interval=1
		kfence.skip_covered_thresh=10
		kfence.burst=1000

Each reproducer was run 10 times (after a fresh reboot), with the
following detection counts for each KFENCE config:

                    | Detection Count out of 10 |
                    |    OOB [1]  |    UAF [2]  |
  ------------------+-------------+-------------+
  Default           |     0/10    |     0/10    |
  Aggressive        |     0/10    |     0/10    |
  AggressiveBurst   |     8/10    |     8/10    |

With the Default and even the Aggressive configs the results are
unsurprising, given KFENCE has not been designed for deterministic bug
detection of small test cases.

However, when enabling burst mode with relatively large burst count,
KFENCE can start to detect heap memory-safety bugs even in simpler test
cases with high probability (in the above cases with ~80% probability).

Link: https://lkml.kernel.org/r/20240805124203.2692278-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:03 -07:00
Jann Horn
17fe833b0d mm: fix (harmless) type confusion in lock_vma_under_rcu()
There is a (harmless) type confusion in lock_vma_under_rcu(): After
vma_start_read(), we have taken the VMA lock but don't know yet whether
the VMA has already been detached and scheduled for RCU freeing.  At this
point, ->vm_start and ->vm_end are accessed.

vm_area_struct contains a union such that ->vm_rcu uses the same memory as
->vm_start and ->vm_end; so accessing ->vm_start and ->vm_end of a
detached VMA is illegal and leads to type confusion between union members.

Fix it by reordering the vma->detached check above the address checks, and
document the rules for RCU readers accessing VMAs.

This will probably change the number of observed VMA_LOCK_MISS events
(since previously, trying to access a detached VMA whose ->vm_rcu has been
scheduled would bail out when checking the fault address against the
rcu_head members reinterpreted as VMA bounds).

Link: https://lkml.kernel.org/r/20240805-fix-vma-lock-type-confusion-v1-1-9f25443a9a71@google.com
Fixes: 50ee325372 ("mm: introduce lock_vma_under_rcu to be used from arch-specific code")
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:03 -07:00
Nhat Pham
e31c38e037 zswap: implement a second chance algorithm for dynamic zswap shrinker
Patch series "improving dynamic zswap shrinker protection scheme", v3.

When experimenting with the memory-pressure based (i.e "dynamic") zswap
shrinker in production, we observed a sharp increase in the number of
swapins, which led to performance regression.  We were able to trace this
regression to the following problems with the shrinker's warm pages
protection scheme: 

1. The protection decays way too rapidly, and the decaying is coupled with
   zswap stores, leading to anomalous patterns, in which a small batch of
   zswap stores effectively erase all the protection in place for the
   warmer pages in the zswap LRU.

   This observation has also been corroborated upstream by Takero Funaki
   (in [1]).

2. We inaccurately track the number of swapped in pages, missing the
   non-pivot pages that are part of the readahead window, while counting
   the pages that are found in the zswap pool.


To alleviate these two issues, this patch series improve the dynamic zswap
shrinker in the following manner:

1. Replace the protection size tracking scheme with a second chance
   algorithm. This new scheme removes the need for haphazard stats
   decaying, and automatically adjusts the pace of pages aging with memory
   pressure, and writeback rate with pool activities: slowing down when
   the pool is dominated with zswpouts, and speeding up when the pool is
   dominated with stale entries.

2. Fix the tracking of the number of swapins to take into account
   non-pivot pages in the readahead window.

With these two changes in place, in a kernel-building benchmark without
any cold data added, the number of swapins is reduced by 64.12%.  This
translate to a 10.32% reduction in build time.  We also observe a 3%
reduction in kernel CPU time.

In another benchmark, with cold data added (to gauge the new algorithm's
ability to offload cold data), the new second chance scheme outperforms
the old protection scheme by around 0.7%, and actually written back around
21% more pages to backing swap device.  So the new scheme is just as good,
if not even better than the old scheme on this front as well.

[1]: https://lore.kernel.org/linux-mm/CAPpodddcGsK=0Xczfuk8usgZ47xeyf4ZjiofdT+ujiyz6V2pFQ@mail.gmail.com/


This patch (of 2):

Current zswap shrinker's heuristics to prevent overshrinking is brittle
and inaccurate, specifically in the way we decay the protection size (i.e
making pages in the zswap LRU eligible for reclaim).

We currently decay protection aggressively in zswap_lru_add() calls.  This
leads to the following unfortunate effect: when a new batch of pages enter
zswap, the protection size rapidly decays to below 25% of the zswap LRU
size, which is way too low.

We have observed this effect in production, when experimenting with the
zswap shrinker: the rate of shrinking shoots up massively right after a
new batch of zswap stores.  This is somewhat the opposite of what we want
originally - when new pages enter zswap, we want to protect both these new
pages AND the pages that are already protected in the zswap LRU.

Replace existing heuristics with a second chance algorithm

1. When a new zswap entry is stored in the zswap pool, its referenced
   bit is set.
2. When the zswap shrinker encounters a zswap entry with the referenced
   bit set, give it a second chance - only flips the referenced bit and
   rotate it in the LRU.
3. If the shrinker encounters the entry again, this time with its
   referenced bit unset, then it can reclaim the entry.

In this manner, the aging of the pages in the zswap LRUs are decoupled
from zswap stores, and picks up the pace with increasing memory pressure
(which is what we want).

The second chance scheme allows us to modulate the writeback rate based on
recent pool activities.  Entries that recently entered the pool will be
protected, so if the pool is dominated by such entries the writeback rate
will reduce proportionally, protecting the workload's workingset.On the
other hand, stale entries will be written back quickly, which increases
the effective writeback rate.

The referenced bit is added at the hole after the `length` field of struct
zswap_entry, so there is no extra space overhead for this algorithm.

We will still maintain the count of swapins, which is consumed and
subtracted from the lru size in zswap_shrinker_count(), to further
penalize past overshrinking that led to disk swapins.  The idea is that
had we considered this many more pages in the LRU active/protected, they
would not have been written back and we would not have had to swapped them
in.

To test this new heuristics, I built the kernel under a cgroup with
memory.max set to 2G, on a host with 36 cores:

With the old shrinker:

real: 263.89s
user: 4318.11s
sys: 673.29s
swapins: 227300.5

With the second chance algorithm:

real: 244.85s
user: 4327.22s
sys: 664.39s
swapins: 94663

(average over 5 runs)

We observe an 1.3% reduction in kernel CPU usage, and around 7.2%
reduction in real time. Note that the number of swapped in pages
dropped by 58%.

[nphamcs@gmail.com: fix a small mistake in the referenced bit documentation]
  Link: https://lkml.kernel.org/r/20240806003403.3142387-1-nphamcs@gmail.com
Link: https://lkml.kernel.org/r/20240805232243.2896283-1-nphamcs@gmail.com
Link: https://lkml.kernel.org/r/20240805232243.2896283-2-nphamcs@gmail.com
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Yosry Ahmed <yosryahmed@google.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Takero Funaki <flintglass@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:02 -07:00
David Hildenbrand
7290840de6 mm: remove follow_page()
All users are gone, let's remove it and any leftovers in comments.  We'll
leave any FOLL/follow_page_() naming cleanups as future work.

Link: https://lkml.kernel.org/r/20240802155524.517137-11-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:01 -07:00
David Hildenbrand
8710f6ed34 mm/huge_memory: convert split_huge_pages_pid() from follow_page() to folio_walk
Let's remove yet another follow_page() user.  Note that we have to do the
split without holding the PTL, after folio_walk_end().  We don't care
about losing the secretmem check in follow_page().

[david@redhat.com: teach can_split_folio() that we are not holding an additional reference]
  Link: https://lkml.kernel.org/r/c75d1c6c-8ea6-424f-853c-1ccda6c77ba2@redhat.com
Link: https://lkml.kernel.org/r/20240802155524.517137-8-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:01 -07:00
David Hildenbrand
aa39ca6940 mm/pagewalk: introduce folio_walk_start() + folio_walk_end()
We want to get rid of follow_page(), and have a more reasonable way to
just lookup a folio mapped at a certain address, perform some checks while
still under PTL, and then only conditionally grab a folio reference if
really required.

Further, we might want to get rid of some walk_page_range*() users that
really only want to temporarily lookup a single folio at a single address.

So let's add a new page table walker that does exactly that, similarly to
GUP also being able to walk hugetlb VMAs.

Add folio_walk_end() as a macro for now: the compiler is not easy to
please with the pte_unmap()->kunmap_local().

Note that one difference between follow_page() and get_user_pages(1) is
that follow_page() will not trigger faults to get something mapped.  So
folio_walk is at least currently not a replacement for get_user_pages(1),
but could likely be extended/reused to achieve something similar in the
future.

Link: https://lkml.kernel.org/r/20240802155524.517137-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:59 -07:00
Andrew Morton
620943d7ee include/linux/mmzone.h: clean up watermark accessors
- we have a helper wmark_pages().  Teach min_wmark_pages(),
  low_wmark_pages(), high_wmark_pages() and promo_wmark_pages() to use
  it instead of open-coding its implementation.

- there's no reason to implement all these things as macros.  Redo them
  in C.

Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kaiyang Zhao <kaiyang2@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:59 -07:00
Kaiyang Zhao
03790c51a4 mm: create promo_wmark_pages and clean up open-coded sites
Patch series "mm: print the promo watermark in zoneinfo", v2.


This patch (of 2):

Define promo_wmark_pages and convert current call sites of wmark_pages
with fixed WMARK_PROMO to using it instead.

Link: https://lkml.kernel.org/r/20240801232548.36604-1-kaiyang2@cs.cmu.edu
Link: https://lkml.kernel.org/r/20240801232548.36604-2-kaiyang2@cs.cmu.edu
Signed-off-by: Kaiyang Zhao <kaiyang2@cs.cmu.edu>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:58 -07:00
David Hildenbrand
17d5f38b33 mm: clarify folio_likely_mapped_shared() documentation for KSM folios
For KSM folios, the function actually does what it is supposed to do: even
having multiple mappings inside the same MM is considered "sharing", as
there is no real relationship between these KSM page mappings -- in
contrast to mapping the same file range twice and having the same
pagecache page mapped twice.

Link: https://lkml.kernel.org/r/20240731160758.808925-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:57 -07:00
David Hildenbrand
94ccd21e9a mm/hugetlb: remove hugetlb_follow_page_mask() leftover
We removed hugetlb_follow_page_mask() in commit 9cb28da546 ("mm/gup:
handle hugetlb in the generic follow_page_mask code") but forgot to
cleanup some leftovers.

While at it, simplify the hugetlb comment, it's overly detailed and rather
confusing.  Stating that we may end up in there during coredumping is
sufficient to explain the PF_DUMPCORE usage.

Link: https://lkml.kernel.org/r/20240731142000.625044-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:57 -07:00
Barry Song
9f101bef40 mm: swap: add nr argument in swapcache_prepare and swapcache_clear to support large folios
Right now, swapcache_prepare() and swapcache_clear() supports one entry
only, to support large folios, we need to handle multiple swap entries.

To optimize stack usage, we iterate twice in __swap_duplicate(): the first
time to verify that all entries are valid, and the second time to apply
the modifications to the entries.

Currently, we're using nr=1 for the existing users.

[v-songbaohua@oppo.com: clarify swap_count_continued and improve readability for  __swap_duplicate]
  Link: https://lkml.kernel.org/r/20240802071817.47081-1-21cnbao@gmail.com
Link: https://lkml.kernel.org/r/20240730071339.107447-2-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Gao Xiang <xiang@kernel.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:56 -07:00
Wei Yang
29943248af mm: improve code consistency with zonelist_* helper functions
Replace direct access to zoneref->zone, zoneref->zone_idx, or
zone_to_nid(zoneref->zone) with the corresponding zonelist_* helper
functions for consistency.

No functional change.

Link: https://lkml.kernel.org/r/20240729091717.464-1-shivankg@amd.com
Co-developed-by: Shivank Garg <shivankg@amd.com>
Signed-off-by: Shivank Garg <shivankg@amd.com>
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:55 -07:00
Lorenzo Stoakes
49b1b8d6f6 mm: move internal core VMA manipulation functions to own file
This patch introduces vma.c and moves internal core VMA manipulation
functions to this file from mmap.c.

This allows us to isolate VMA functionality in a single place such that we
can create userspace testing code that invokes this functionality in an
environment where we can implement simple unit tests of core
functionality.

This patch ensures that core VMA functionality is explicitly marked as
such by its presence in mm/vma.h.

It also places the header includes required by vma.c in vma_internal.h,
which is simply imported by vma.c.  This makes the VMA functionality
testable, as userland testing code can simply stub out functionality as
required.

Link: https://lkml.kernel.org/r/c77a6aafb4c42aaadb8e7271a853658cbdca2e22.1722251717.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Gow <davidgow@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Kees Cook <kees@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Rae Moar <rmoar@google.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:54 -07:00
Lorenzo Stoakes
d61f0d5968 mm: move vma_shrink(), vma_expand() to internal header
The vma_shrink() and vma_expand() functions are internal VMA manipulation
functions which we ought to abstract for use outside of memory management
code.

To achieve this, we replace shift_arg_pages() in fs/exec.c with an
invocation of a new relocate_vma_down() function implemented in mm/mmap.c,
which enables us to also move move_page_tables() and vma_iter_prev_range()
to internal.h.

The purpose of doing this is to isolate key VMA manipulation functions in
order that we can both abstract them and later render them easily
testable.

Link: https://lkml.kernel.org/r/3cfcd9ec433e032a85f636fdc0d7d98fafbd19c5.1722251717.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Gow <davidgow@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Kees Cook <kees@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Rae Moar <rmoar@google.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:54 -07:00
Lorenzo Stoakes
fa04c08f3c mm: move vma_modify() and helpers to internal header
These are core VMA manipulation functions which invoke VMA splitting and
merging and should not be directly accessed from outside of mm/.

Link: https://lkml.kernel.org/r/5efde0c6342a8860d5ffc90b415f3989fd8ed0b2.1722251717.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Gow <davidgow@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Kees Cook <kees@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Rae Moar <rmoar@google.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:54 -07:00
Lorenzo Stoakes
a17c7d8fd2 userfaultfd: move core VMA manipulation logic to mm/userfaultfd.c
Patch series "Make core VMA operations internal and testable", v4.

There are a number of "core" VMA manipulation functions implemented in
mm/mmap.c, notably those concerning VMA merging, splitting, modifying,
expanding and shrinking, which logically don't belong there.

More importantly this functionality represents an internal implementation
detail of memory management and should not be exposed outside of mm/
itself.

This patch series isolates core VMA manipulation functionality into its
own file, mm/vma.c, and provides an API to the rest of the mm code in
mm/vma.h.

Importantly, it also carefully implements mm/vma_internal.h, which
specifies which headers need to be imported by vma.c, leading to the very
useful property that vma.c depends only on mm/vma.h and mm/vma_internal.h.

This means we can then re-implement vma_internal.h in userland, adding
shims for kernel mechanisms as required, allowing us to unit test internal
VMA functionality.

This testing is useful as opposed to an e.g.  kunit implementation as this
way we can avoid all external kernel side-effects while testing, run tests
VERY quickly, and iterate on and debug problems quickly.

Excitingly this opens the door to, in the future, recreating precise
problems observed in production in userland and very quickly debugging
problems that might otherwise be very difficult to reproduce.

This patch series takes advantage of existing shim logic and full userland
maple tree support contained in tools/testing/radix-tree/ and
tools/include/linux/, separating out shared components of the radix tree
implementation to provide this testing.

Kernel functionality is stubbed and shimmed as needed in
tools/testing/vma/ which contains a fully functional userland
vma_internal.h file and which imports mm/vma.c and mm/vma.h to be directly
tested from userland.

A simple, skeleton testing implementation is provided in
tools/testing/vma/vma.c as a proof-of-concept, asserting that simple VMA
merge, modify (testing split), expand and shrink functionality work
correctly.


This patch (of 4):

This patch forms part of a patch series intending to separate out VMA
logic and render it testable from userspace, which requires that core
manipulation functions be exposed in an mm/-internal header file.

In order to do this, we must abstract APIs we wish to test, in this
instance functions which ultimately invoke vma_modify().

This patch therefore moves all logic which ultimately invokes vma_modify()
to mm/userfaultfd.c, trying to transfer code at a functional granularity
where possible.

[lorenzo.stoakes@oracle.com: fix user-after-free in userfaultfd_clear_vma()]
  Link: https://lkml.kernel.org/r/3c947ddc-b804-49b7-8fe9-3ea3ca13def5@lucifer.local
Link: https://lkml.kernel.org/r/cover.1722251717.git.lorenzo.stoakes@oracle.com
Link: https://lkml.kernel.org/r/50c3ed995fd81c45876c86304c8a00bf3e396cfd.1722251717.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Gow <davidgow@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Kees Cook <kees@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Rae Moar <rmoar@google.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:53 -07:00
David Finkel
c6f53ed8f2 mm, memcg: cg2 memory{.swap,}.peak write handlers
Patch series "mm, memcg: cg2 memory{.swap,}.peak write handlers", v7.


This patch (of 2):

Other mechanisms for querying the peak memory usage of either a process or
v1 memory cgroup allow for resetting the high watermark.  Restore parity
with those mechanisms, but with a less racy API.

For example:
 - Any write to memory.max_usage_in_bytes in a cgroup v1 mount resets
   the high watermark.
 - writing "5" to the clear_refs pseudo-file in a processes's proc
   directory resets the peak RSS.

This change is an evolution of a previous patch, which mostly copied the
cgroup v1 behavior, however, there were concerns about races/ownership
issues with a global reset, so instead this change makes the reset
filedescriptor-local.

Writing any non-empty string to the memory.peak and memory.swap.peak
pseudo-files reset the high watermark to the current usage for subsequent
reads through that same FD.

Notably, following Johannes's suggestion, this implementation moves the
O(FDs that have written) behavior onto the FD write(2) path.  Instead, on
the page-allocation path, we simply add one additional watermark to
conditionally bump per-hierarchy level in the page-counter.

Additionally, this takes Longman's suggestion of nesting the
page-charging-path checks for the two watermarks to reduce the number of
common-case comparisons.

This behavior is particularly useful for work scheduling systems that need
to track memory usage of worker processes/cgroups per-work-item.  Since
memory can't be squeezed like CPU can (the OOM-killer has opinions), these
systems need to track the peak memory usage to compute system/container
fullness when binpacking workitems.

Most notably, Vimeo's use-case involves a system that's doing global
binpacking across many Kubernetes pods/containers, and while we can use
PSI for some local decisions about overload, we strive to avoid packing
workloads too tightly in the first place.  To facilitate this, we track
the peak memory usage.  However, since we run with long-lived workers (to
amortize startup costs) we need a way to track the high watermark while a
work-item is executing.  Polling runs the risk of missing short spikes
that last for timescales below the polling interval, and peak memory
tracking at the cgroup level is otherwise perfect for this use-case.

As this data is used to ensure that binpacked work ends up with sufficient
headroom, this use-case mostly avoids the inaccuracies surrounding
reclaimable memory.

Link: https://lkml.kernel.org/r/20240730231304.761942-1-davidf@vimeo.com
Link: https://lkml.kernel.org/r/20240729143743.34236-1-davidf@vimeo.com
Link: https://lkml.kernel.org/r/20240729143743.34236-2-davidf@vimeo.com
Signed-off-by: David Finkel <davidf@vimeo.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Waiman Long <longman@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:53 -07:00
David Hildenbrand
3290ef3c7f s390/uv: drop arch_make_page_accessible()
All code was converted to using arch_make_folio_accessible(), let's drop
arch_make_page_accessible().

Link: https://lkml.kernel.org/r/20240729183844.388481-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:53 -07:00
David Hildenbrand
e5a41fc777 mm: simplify arch_make_folio_accessible()
Patch series "mm: remove arch_make_page_accessible()".

Now that s390x implements arch_make_folio_accessible(), let's convert
remaining users to use arch_make_folio_accessible() instead so we can
remove arch_make_page_accessible().


This patch (of 3):

Now that s390x implements HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE, let's turn
generic arch_make_folio_accessible() into a NOP: there are no other
targets that implement HAVE_ARCH_MAKE_PAGE_ACCESSIBLE but not
HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE.

Link: https://lkml.kernel.org/r/20240729183844.388481-1-david@redhat.com
Link: https://lkml.kernel.org/r/20240729183844.388481-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:52 -07:00
David Hildenbrand
188cac58a8 mm/hugetlb: enforce that PMD PT sharing has split PMD PT locks
Sharing page tables between processes but falling back to per-MM page
table locks cannot possibly work.

So, let's make sure that we do have split PMD locks by adding a new
Kconfig option and letting that depend on CONFIG_SPLIT_PMD_PTLOCKS.

Link: https://lkml.kernel.org/r/20240726150728.3159964-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:51 -07:00
David Hildenbrand
394290cba9 mm: turn USE_SPLIT_PTE_PTLOCKS / USE_SPLIT_PTE_PTLOCKS into Kconfig options
Patch series "mm: split PTE/PMD PT table Kconfig cleanups+clarifications".

This series is a follow up to the fixes:
	"[PATCH v1 0/2] mm/hugetlb: fix hugetlb vs. core-mm PT locking"

When working on the fixes, I wondered why 8xx is fine (-> never uses split
PT locks) and how PT locking even works properly with PMD page table
sharing (-> always requires split PMD PT locks).

Let's improve the split PT lock detection, make hugetlb properly depend on
it and make 8xx bail out if it would ever get enabled by accident.

As an alternative to patch #3 we could extend the Kconfig
SPLIT_PTE_PTLOCKS option from patch #2 -- but enforcing it closer to the
code that actually implements it feels a bit nicer for documentation
purposes, and there is no need to actually disable it because it should
always be disabled (!SMP).

Did a bunch of cross-compilations to make sure that split PTE/PMD PT locks
are still getting used where we would expect them.

[1] https://lkml.kernel.org/r/20240725183955.2268884-1-david@redhat.com


This patch (of 3):

Let's clean that up a bit and prepare for depending on
CONFIG_SPLIT_PMD_PTLOCKS in other Kconfig options.

More cleanups would be reasonable (like the arch-specific "depends on" for
CONFIG_SPLIT_PTE_PTLOCKS), but we'll leave that for another day.

Link: https://lkml.kernel.org/r/20240726150728.3159964-1-david@redhat.com
Link: https://lkml.kernel.org/r/20240726150728.3159964-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:51 -07:00
Roman Gushchin
57979fabff mm: page_counters: initialize usage using ATOMIC_LONG_INIT() macro
When a page_counter structure is initialized, there is no need to use an
atomic set operation to initialize the usage counter because at this point
the structure is not visible to anybody else.  ATOMIC_LONG_INIT() is what
should be used in such cases.

Link: https://lkml.kernel.org/r/20240726203110.1577216-4-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:51 -07:00
Roman Gushchin
941ce63523 mm: page_counters: put page_counter_calculate_protection() under CONFIG_MEMCG
Put page_counter_calculate_protection() under CONFIG_MEMCG.

The protection functionality (min/low limits) is not supported by any
other cgroup subsystem, so page_counter_calculate_protection() and related
static effective_protection() can be compiled out if CONFIG_MEMCG is not
enabled.

Link: https://lkml.kernel.org/r/20240726203110.1577216-3-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:51 -07:00
Roman Gushchin
f77bd4b14c mm: memcg: don't call propagate_protected_usage() needlessly
Patch series "mm: memcg: page counters optimizations", v3.

This patchset contains 3 independent small optimizations of page counters.


This patch (of 3):

Memory protection (min/low) requires a constant tracking of protected
memory usage.  propagate_protected_usage() is called on each page counters
update and does a number of operations even in cases when the actual
memory protection functionality is not supported (e.g.  hugetlb cgroups or
memcg swap counters).

It's obviously inefficient and leads to a waste of CPU cycles.  It can be
addressed by calling propagate_protected_usage() only for the counters
which do support memory guarantees.  As of now it's only memcg->memory -
the unified memory memcg counter.

Link: https://lkml.kernel.org/r/20240726203110.1577216-2-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:50 -07:00
Pasha Tatashin
fbe76a6557 task_stack: uninline stack_not_used
Given that stack_not_used() is not performance critical function
uninline it.

Link: https://lkml.kernel.org/r/20240730150158.832783-4-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20240724203322.2765486-4-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:49 -07:00
Pasha Tatashin
c4a6fce856 vmstat: kernel stack usage histogram
As part of the dynamic kernel stack project, we need to know the amount of
data that can be saved by reducing the default kernel stack size [1].

Provide a kernel stack usage histogram to aid in optimizing kernel stack
sizes and minimizing memory waste in large-scale environments.  The
histogram divides stack usage into power-of-two buckets and reports the
results in /proc/vmstat.  This information is especially valuable in
environments with millions of machines, where even small optimizations can
have a significant impact.

The histogram data is presented in /proc/vmstat with entries like
"kstack_1k", "kstack_2k", and so on, indicating the number of threads that
exited with stack usage falling within each respective bucket.

Example outputs:
Intel:
$ grep kstack /proc/vmstat
kstack_1k 3
kstack_2k 188
kstack_4k 11391
kstack_8k 243
kstack_16k 0

ARM with 64K page_size:
$ grep kstack /proc/vmstat
kstack_1k 1
kstack_2k 340
kstack_4k 25212
kstack_8k 1659
kstack_16k 0
kstack_32k 0
kstack_64k 0

Note: once the dynamic kernel stack is implemented it will depend on the
implementation the usability of this feature: On hardware that supports
faults on kernel stacks, we will have other metrics that show the total
number of pages allocated for stacks.  On hardware where faults are not
supported, we will most likely have some optimization where only some
threads are extended, and for those, these metrics will still be very
useful.

[1] https://lwn.net/Articles/974367

Link: https://lkml.kernel.org/r/20240730150158.832783-3-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20240724203322.2765486-3-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:49 -07:00
Zi Yan
2a28713a67 memory tiering: introduce folio_use_access_time() check
If memory tiering mode is on and a folio is not in the top tier memory,
folio's cpupid field is repurposed to store page access time.  Instead of
an open coded check, use a function to encapsulate the check.

Link: https://lkml.kernel.org/r/20240724130115.793641-3-ziy@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:47 -07:00
Muchun Song
4fd568faf6 mm: kmem: remove mem_cgroup_from_obj()
There is no user of mem_cgroup_from_obj(), remove it.

Link: https://lkml.kernel.org/r/20240718091821.44740-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:46 -07:00
Baolin Wang
6beeab870e mm: shmem: move shmem_huge_global_enabled() into shmem_allowable_huge_orders()
Move shmem_huge_global_enabled() into shmem_allowable_huge_orders(), so
that shmem_allowable_huge_orders() can also help to find the allowable
huge orders for tmpfs.  Moreover the shmem_huge_global_enabled() can
become static.  While we are at it, passing the vma instead of mm for
shmem_huge_global_enabled() makes code cleaner.

No functional changes.

Link: https://lkml.kernel.org/r/8e825146bb29ee1a1c7bd64d2968ff3e19be7815.1721626645.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:44 -07:00
Baolin Wang
d58a2a581f mm: shmem: rename shmem_is_huge() to shmem_huge_global_enabled()
shmem_is_huge() is now used to check if the top-level huge page is
enabled, thus rename it to reflect its usage.

Link: https://lkml.kernel.org/r/da53296e0ab6359aa083561d9dc01e4223d60fbe.1721626645.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:44 -07:00
Danilo Krummrich
590b9d576c mm: kvmalloc: align kvrealloc() with krealloc()
Besides the obvious (and desired) difference between krealloc() and
kvrealloc(), there is some inconsistency in their function signatures and
behavior:

 - krealloc() frees the memory when the requested size is zero, whereas
   kvrealloc() simply returns a pointer to the existing allocation.

 - krealloc() behaves like kmalloc() if a NULL pointer is passed, whereas
   kvrealloc() does not accept a NULL pointer at all and, if passed,
   would fault instead.

 - krealloc() is self-contained, whereas kvrealloc() relies on the caller
   to provide the size of the previous allocation.

Inconsistent behavior throughout allocation APIs is error prone, hence
make kvrealloc() behave like krealloc(), which seems superior in all
mentioned aspects.

Besides that, implementing kvrealloc() by making use of krealloc() and
vrealloc() provides oppertunities to grow (and shrink) allocations more
efficiently.  For instance, vrealloc() can be optimized to allocate and
map additional pages to grow the allocation or unmap and free unused pages
to shrink the allocation.

[dakr@kernel.org: document concurrency restrictions]
  Link: https://lkml.kernel.org/r/20240725125442.4957-1-dakr@kernel.org
[dakr@kernel.org: disable KASAN when switching to vmalloc]
  Link: https://lkml.kernel.org/r/20240730185049.6244-2-dakr@kernel.org
[dakr@kernel.org: properly document __GFP_ZERO behavior]
  Link: https://lkml.kernel.org/r/20240730185049.6244-5-dakr@kernel.org
Link: https://lkml.kernel.org/r/20240722163111.4766-3-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Chandan Babu R <chandan.babu@oracle.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:44 -07:00
Danilo Krummrich
3ddc2fefe6 mm: vmalloc: implement vrealloc()
Patch series "Align kvrealloc() with krealloc()", v2.

Besides the obvious (and desired) difference between krealloc() and
kvrealloc(), there is some inconsistency in their function signatures and
behavior:

 - krealloc() frees the memory when the requested size is zero, whereas
   kvrealloc() simply returns a pointer to the existing allocation.

 - krealloc() behaves like kmalloc() if a NULL pointer is passed, whereas
   kvrealloc() does not accept a NULL pointer at all and, if passed, would fault
   instead.

 - krealloc() is self-contained, whereas kvrealloc() relies on the caller to
   provide the size of the previous allocation.

Inconsistent behavior throughout allocation APIs is error prone, hence
make kvrealloc() behave like krealloc(), which seems superior in all
mentioned aspects.

In order to be able to get rid of kvrealloc()'s oldsize parameter,
introduce vrealloc() and make use of it in kvrealloc().

Making use of vrealloc() in kvrealloc() also provides oppertunities to
grow (and shrink) allocations more efficiently.  For instance, vrealloc()
can be optimized to allocate and map additional pages to grow the
allocation or unmap and free unused pages to shrink the allocation.

Besides the above, those functions are required by Rust's allocator abstractons
[1] (rework based on this series in [2]). With `Vec` or `KVec` respectively,
potentially growing (and shrinking) data structures are rather common.

[1] https://lore.kernel.org/lkml/20240704170738.3621-1-dakr@redhat.com/
[2] https://git.kernel.org/pub/scm/linux/kernel/git/dakr/linux.git/log/?h=rust/mm


This patch (of 2):

Implement vrealloc() analogous to krealloc().

Currently, krealloc() requires the caller to pass the size of the previous
memory allocation, which, instead, should be self-contained.

We attempt to fix this in a subsequent patch which, in order to do so,
requires vrealloc().

Besides that, we need realloc() functions for kernel allocators in Rust
too.  With `Vec` or `KVec` respectively, potentially growing (and
shrinking) data structures are rather common.

[dakr@kernel.org: fix missing nommu implementation]
  Link: https://lkml.kernel.org/r/20240725141227.13954-1-dakr@kernel.org
[dakr@kernel.org: document concurrency restrictions]
  Link: https://lkml.kernel.org/r/20240725125442.4957-1-dakr@kernel.org
[dakr@kernel.org: consider spare memory for __GFP_ZERO]
  Link: https://lkml.kernel.org/r/20240730185049.6244-3-dakr@kernel.org
[dakr@kernel.org: properly document __GFP_ZERO behavior]
  Link: https://lkml.kernel.org/r/20240730185049.6244-4-dakr@kernel.org
Link: https://lkml.kernel.org/r/20240722163111.4766-1-dakr@kernel.org
Link: https://lkml.kernel.org/r/20240722163111.4766-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Chandan Babu R <chandan.babu@oracle.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:43 -07:00
Matthew Cassell
5fe690a594 mm: add node_reclaim successes to VM event counters
/proc/vmstat currently shows the number of node_reclaim() failures when
vm.zone_reclaim_mode is set appropriately.  It would be convenient to have
the number of successes right next to zone_reclaim_failed (similar to
compaction and migration).

While just a trivially addition to the vmstat file.  It was helpful during
benchmarking to not have to probe node_reclaim() to observe the
success/failure ratio.

Link: https://lkml.kernel.org/r/20240722171316.7517-1-mcassell411@gmail.com
Signed-off-by: Matthew Cassell <mcassell411@gmail.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:43 -07:00
Linus Torvalds
6b9ffc4595 four cifs.ko client fixes
-----BEGIN PGP SIGNATURE-----
 
 iQGzBAABCgAdFiEE6fsu8pdIjtWE/DpLiiy9cAdyT1EFAmbTuKMACgkQiiy9cAdy
 T1GsHwwAnrVfxJ+ZiAH0wbfyFcgRLOAePeADcedn4QWQaPbmyjqqQbHfiwRwDa5X
 sICpnxCS+3MM9aahA7G4FOZNle/DexmFUODScESmYMfdqt4hMGzGbi9KhA4l7TY8
 rcewHNpbAiPW3S0y/VtOBoXXskURMEL6+KCaBwE3u990jimJtCxPie4PQbfI/V6O
 4Qjqc8qjryPo70ru4g72h/LfJdaDKxV/JYymDyhhu5/Gf7PPbv0QKZ9hhxhpc6Y4
 81IcJ7S4JnLA8V9nrglrbV3ymvOCXNH0UQRHOa4Hc6H7MmrVj1aE5nu0/nfgVaOh
 iaaKfuuv6ItDQBWqUg6tHqM8DSPONJkbhuFkXqL/rOmrl7B0G5T1UBlt3ZqNZEy5
 bEX1VCqCDQRsr1nUCxC7t5r03teXeNq59nWg/JWBBbLohWLp4Dw4eKW0xlKyo3VT
 Oxho3E8DnVXRu8MdTF/OeFJllp71KY3ujt2wm8uu+f5H45vz9mBN0UEUAx6hoh3c
 SsxufLuG
 =l4NV
 -----END PGP SIGNATURE-----

Merge tag 'v6.11-rc5-smb-client-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull smb client fixes from Steve French:

 - copy_file_range fix

 - two read fixes including read past end of file rc fix and read retry
   crediting fix

 - falloc zero range fix

* tag 'v6.11-rc5-smb-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: Fix FALLOC_FL_ZERO_RANGE to preflush buffered part of target region
  cifs: Fix copy offload to flush destination region
  netfs, cifs: Fix handling of short DIO read
  cifs: Fix lack of credit renegotiation on read retry
2024-09-01 15:49:26 +12:00
Linus Torvalds
35667a2969 ARM: SoC fixes for 6.11, part 2
There is a fairly large number of bug fixes for Qualcomm platforms,
 most of them addressing issues with the devicetree files for the
 newly added Snapdragon X1 based laptops to make them more reliable.
 The Qualcomm driver changes address a few build-time issues as well
 as runtime problems in the tzmem and scm firmware, the USB Type-C
 driver, and the cmd-db and pmic_glink soc drivers.
 
 The NXP i.MX usually gets a bunch of devicetree fixes that is proportional
 to the number of supported machines. This includes both warning fixes
 and correctness for the 64-bit i.MX9, i.MX8 and layerscape platforms,
 as well as a single fix for a 32-bit i.MX6 based board.
 
 The other changes are the usual minor changes, including an update to the
 MAINTAINERS file, an omap3 dts file and a SoC driver for mpfs (risc-v).
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEiK/NIGsWEZVxh/FrYKtH/8kJUicFAmbSNOgACgkQYKtH/8kJ
 UieuWg//eW9qg16Fw7ZeEDSrq7s7Mrr03zcF+Xqb1wpZZqDbUqgSWqaDDapd//bW
 st7eR2rxm5yySBRbYFNa/jjB7YQA1GSlYtFn3cBEe/lFiuhOeP5yWwKTT05yeWDr
 RzkPSDIt30YDsYV6+k5HpyzRNeuOd7QaVOz9XKqnEgzuRKC89OcSkHmXQUhvvbrg
 f+5/uSFTZBAYjUpuH3ZRX9elRYsHSYlsmLI71HWRIBZrvNWwv3O4N0nySbCdhE0V
 8hb3fCo/39rdjWjKuGHigsvxMLLmooFNvu/r/oZtqUjFDIjOkVzxI14K/yl2al7v
 nmEHnwFqTsTIGP21CmRV4fzrS/80gld3ieLavC9kZaWqfV9yMjF1+jg40qsrUXcR
 /Gfzq7XCrqx9CpFA62uytjkQZI5tk9Ip9FQHK80+OsDq8/zCJs77NIwR26VNT3O/
 HIf9yTdC4bzZW1hUpTsIy+/piSWja5kkSKHn5Zcqby05hPUjWe/utiBKW3lTE9OI
 EJ4swrHOenGea0AEeR2Rp5WOVfq26q12m4GYCi5YM+FGr64KHf5URQ1GoRTxorAx
 YLa8xGm88CfIU3rnW90b2/5lYgqAyL3xEq9p1qt9HmZx/0SuoGbV1EekgfPd52yV
 hrkn2gnNGS+A2ldqSRGZVJQSxKIpISORDj4y3sAI+JEQmm0UEM0=
 =tK5m
 -----END PGP SIGNATURE-----

Merge tag 'arm-fixes-6.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc

Pull ARM SoC fixes from Arnd Bergmann:
 "There is a fairly large number of bug fixes for Qualcomm platforms,
  most of them addressing issues with the devicetree files for the newly
  added Snapdragon X1 based laptops to make them more reliable.

  The Qualcomm driver changes address a few build-time issues as well as
  runtime problems in the tzmem and scm firmware, the USB Type-C driver,
  and the cmd-db and pmic_glink soc drivers.

  The NXP i.MX usually gets a bunch of devicetree fixes that is
  proportional to the number of supported machines. This includes both
  warning fixes and correctness for the 64-bit i.MX9, i.MX8 and
  layerscape platforms, as well as a single fix for a 32-bit i.MX6 based
  board.

  The other changes are the usual minor changes, including an update to
  the MAINTAINERS file, an omap3 dts file and a SoC driver for mpfs
  (risc-v)"

* tag 'arm-fixes-6.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (50 commits)
  firmware: microchip: fix incorrect error report of programming:timeout on success
  soc: qcom: pd-mapper: Fix singleton refcount
  firmware: qcom: tzmem: disable sdm670 platform
  soc: qcom: pmic_glink: Actually communicate when remote goes down
  usb: typec: ucsi: Move unregister out of atomic section
  soc: qcom: pmic_glink: Fix race during initialization
  firmware: qcom: qseecom: remove unused functions
  firmware: qcom: tzmem: fix virtual-to-physical address conversion
  firmware: qcom: scm: Mark get_wq_ctx() as atomic call
  arm64: dts: qcom: x1e80100: Fix Adreno SMMU global interrupt
  arm64: dts: qcom: disable GPU on x1e80100 by default
  arm64: dts: imx8mm-phygate: fix typo pinctrcl-0
  arm64: dts: imx95: correct L3Cache cache-sets
  arm64: dts: imx95: correct a55 power-domains
  arm64: dts: freescale: imx93-tqma9352-mba93xxla: fix typo
  arm64: dts: freescale: imx93-tqma9352: fix CMA alloc-ranges
  ARM: dts: imx6dl-yapp43: Increase LED current to match the yapp4 HW design
  arm64: dts: imx93: update default value for snps,clk-csr
  arm64: dts: freescale: tqma9352: Fix watchdog reset
  arm64: dts: imx8mp-beacon-kit: Fix Stereo Audio on WM8962
  ...
2024-09-01 06:42:13 +12:00
Linus Torvalds
13c6bba601 IOMMU Fixes for Linux v6.11-rc5
Including:
 
 	- Fix a device-stall problem in bad io-page-fault setups (faults
 	  received from devices with no supporting domain attached).
 
 	- Context flush fix for Intel VT-d.
 
 	- Do not allow non-read+non-write mapping through iommufd as most
 	  implementations can not handle that.
 
 	- Fix a possible infinite-loop issue in map_pages() path.
 
 	- Add Jean-Philippe as reviewer for SMMUv3 SVA support
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEr9jSbILcajRFYWYyK/BELZcBGuMFAmbRvfEACgkQK/BELZcB
 GuOB8w//WLapQpxMw9w+4l3Z3SqxB5gSPF6pdCJwYRrpFGBX1yNZ0vWtF2TpKtOC
 NaMa/EC1C2FWjcArCP21uFtDvN04FgXSVl6sjFUHsUf+YALrUfljQk/XFI4SenTq
 PtvPv8PVGbhqLtdJDXMlQWBN3RX0qK/PIFmuUX5ySBk7J7k5QyBi2HEuK2DbPM7j
 +LMnyTHj5Aa2jRz/NSCDIRKbSFJKgvd8apval2VX0zljjpyqk5KmHHjkLtiOiTTI
 G6ZJlRYCn98eTLU2ww8b7/y0vVYop7C1Q7Cyds/72xvW+a3jbSRIGf6yqtmdbMYd
 faxRng5rWHWsq3XMZC+Ts9k2FA3pUIvOmfptCFfrQYYXvZI6dD6o7uMko6SF82n4
 xEy+H6AEWZXF70xaJDp1cn1PpURJgJly/l/6qAIB746qNT7j/CcOOha1bpbCy81x
 EIOl0B4wyJGjQnxjKsH01K9ec3uT6rugbpFEE9PL8l25khhyweBwuQWc2EVxRZgH
 ICH4pCmvU9Wy6mpXL2R/SyzECWjgg0oJr+pq3Yxv7xufSGQswWJ/StFozSBHnH01
 OGGA/2xMrNeRzlm4PZfRzdAiCfYX9kEodiF1jGLA4B1V5Tx/y1LSX7W/nCeZmlRz
 /OhEC07DWZumeSCTe5I+BmZwiXh/DEAlUypDQkVKaaeGltlyvl8=
 =8XuD
 -----END PGP SIGNATURE-----

Merge tag 'iommu-fixes-v6.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux

Pull iommu fixes from Joerg Roedel:

 - Fix a device-stall problem in bad io-page-fault setups (faults
   received from devices with no supporting domain attached).

 - Context flush fix for Intel VT-d.

 - Do not allow non-read+non-write mapping through iommufd as most
   implementations can not handle that.

 - Fix a possible infinite-loop issue in map_pages() path.

 - Add Jean-Philippe as reviewer for SMMUv3 SVA support

* tag 'iommu-fixes-v6.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux:
  MAINTAINERS: Add Jean-Philippe as SMMUv3 SVA reviewer
  iommu: Do not return 0 from map_pages if it doesn't do anything
  iommufd: Do not allow creating areas without READ or WRITE
  iommu/vt-d: Fix incorrect domain ID in context flush helper
  iommu: Handle iommu faults for a bad iopf setup
2024-08-31 06:11:34 +12:00