Commit Graph

398 Commits

Author SHA1 Message Date
Christoph Lameter (Ampere)
786d5cc2b9 Update Christoph's Email address and make it consistent
Use cl@gentwo.org throughout and remove the old email addresses.

Link: https://lkml.kernel.org/r/8b962f57-4d98-cbb0-cd82-b6ba456733e8@gentwo.org
Signed-off-by: Christoph Lameter <cl@gentwo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-12 23:50:31 -07:00
Linus Torvalds
a50b4fe095 A treewide hrtimer timer cleanup
hrtimers are initialized with hrtimer_init() and a subsequent store to
   the callback pointer. This turned out to be suboptimal for the upcoming
   Rust integration and is obviously a silly implementation to begin with.
 
   This cleanup replaces the hrtimer_init(T); T->function = cb; sequence
   with hrtimer_setup(T, cb);
 
   The conversion was done with Coccinelle and a few manual fixups.
 
   Once the conversion has completely landed in mainline, hrtimer_init()
   will be removed and the hrtimer::function becomes a private member.
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Merge tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer cleanups from Thomas Gleixner:
 "A treewide hrtimer timer cleanup

  hrtimers are initialized with hrtimer_init() and a subsequent store to
  the callback pointer. This turned out to be suboptimal for the
  upcoming Rust integration and is obviously a silly implementation to
  begin with.

  This cleanup replaces the hrtimer_init(T); T->function = cb; sequence
  with hrtimer_setup(T, cb);

  The conversion was done with Coccinelle and a few manual fixups.

  Once the conversion has completely landed in mainline, hrtimer_init()
  will be removed and the hrtimer::function becomes a private member"

* tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (100 commits)
  wifi: rt2x00: Switch to use hrtimer_update_function()
  io_uring: Use helper function hrtimer_update_function()
  serial: xilinx_uartps: Use helper function hrtimer_update_function()
  ASoC: fsl: imx-pcm-fiq: Switch to use hrtimer_setup()
  RDMA: Switch to use hrtimer_setup()
  virtio: mem: Switch to use hrtimer_setup()
  drm/vmwgfx: Switch to use hrtimer_setup()
  drm/xe/oa: Switch to use hrtimer_setup()
  drm/vkms: Switch to use hrtimer_setup()
  drm/msm: Switch to use hrtimer_setup()
  drm/i915/request: Switch to use hrtimer_setup()
  drm/i915/uncore: Switch to use hrtimer_setup()
  drm/i915/pmu: Switch to use hrtimer_setup()
  drm/i915/perf: Switch to use hrtimer_setup()
  drm/i915/gvt: Switch to use hrtimer_setup()
  drm/i915/huc: Switch to use hrtimer_setup()
  drm/amdgpu: Switch to use hrtimer_setup()
  stm class: heartbeat: Switch to use hrtimer_setup()
  i2c: Switch to use hrtimer_setup()
  iio: Switch to use hrtimer_setup()
  ...
2025-03-25 10:54:15 -07:00
Vlastimil Babka
dea2d9221e Merge branch 'slab/for-6.15/kfree_rcu_tiny' into slab/for-next
Merge the slab feature branch kfree_rcu_tiny for 6.15:

- Move the TINY_RCU kvfree_rcu() implementation from RCU to SLAB
  subsystem and cleanup its integration.
2025-03-20 10:33:38 +01:00
Kevin Brodsky
12f4888c9d mm/slab: simplify SLAB_* flag handling
SLUB is the only remaining allocator. We can therefore get rid of
the logic for allocator-specific flags:

* Merge SLAB_CACHE_FLAGS into SLAB_CORE_FLAGS.

* Remove CACHE_CREATE_MASK and instead mask out SLAB_DEBUG_FLAGS if
  !CONFIG_SLUB_DEBUG. SLAB_DEBUG_FLAGS is now defined
  unconditionally (no impact on existing code, which ignores it if
  !CONFIG_SLUB_DEBUG).

* Define SLAB_FLAGS_PERMITTED in terms of SLAB_CORE_FLAGS and
  SLAB_DEBUG_FLAGS (no functional change).

While at it also remove misleading comments that suggest that
multiple allocators are available.

Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-03-04 08:53:50 +01:00
Uladzislau Rezki (Sony)
dfd3df31c9 mm/slab/kvfree_rcu: Switch to WQ_MEM_RECLAIM wq
Currently kvfree_rcu() APIs use a system workqueue which is
"system_unbound_wq" to driver RCU machinery to reclaim a memory.

Recently, it has been noted that the following kernel warning can
be observed:

<snip>
workqueue: WQ_MEM_RECLAIM nvme-wq:nvme_scan_work is flushing !WQ_MEM_RECLAIM events_unbound:kfree_rcu_work
  WARNING: CPU: 21 PID: 330 at kernel/workqueue.c:3719 check_flush_dependency+0x112/0x120
  Modules linked in: intel_uncore_frequency(E) intel_uncore_frequency_common(E) skx_edac(E) ...
  CPU: 21 UID: 0 PID: 330 Comm: kworker/u144:6 Tainted: G            E      6.13.2-0_g925d379822da #1
  Hardware name: Wiwynn Twin Lakes MP/Twin Lakes Passive MP, BIOS YMM20 02/01/2023
  Workqueue: nvme-wq nvme_scan_work
  RIP: 0010:check_flush_dependency+0x112/0x120
  Code: 05 9a 40 14 02 01 48 81 c6 c0 00 00 00 48 8b 50 18 48 81 c7 c0 00 00 00 48 89 f9 48 ...
  RSP: 0018:ffffc90000df7bd8 EFLAGS: 00010082
  RAX: 000000000000006a RBX: ffffffff81622390 RCX: 0000000000000027
  RDX: 00000000fffeffff RSI: 000000000057ffa8 RDI: ffff88907f960c88
  RBP: 0000000000000000 R08: ffffffff83068e50 R09: 000000000002fffd
  R10: 0000000000000004 R11: 0000000000000000 R12: ffff8881001a4400
  R13: 0000000000000000 R14: ffff88907f420fb8 R15: 0000000000000000
  FS:  0000000000000000(0000) GS:ffff88907f940000(0000) knlGS:0000000000000000
  CR2: 00007f60c3001000 CR3: 000000107d010005 CR4: 00000000007726f0
  PKRU: 55555554
  Call Trace:
   <TASK>
   ? __warn+0xa4/0x140
   ? check_flush_dependency+0x112/0x120
   ? report_bug+0xe1/0x140
   ? check_flush_dependency+0x112/0x120
   ? handle_bug+0x5e/0x90
   ? exc_invalid_op+0x16/0x40
   ? asm_exc_invalid_op+0x16/0x20
   ? timer_recalc_next_expiry+0x190/0x190
   ? check_flush_dependency+0x112/0x120
   ? check_flush_dependency+0x112/0x120
   __flush_work.llvm.1643880146586177030+0x174/0x2c0
   flush_rcu_work+0x28/0x30
   kvfree_rcu_barrier+0x12f/0x160
   kmem_cache_destroy+0x18/0x120
   bioset_exit+0x10c/0x150
   disk_release.llvm.6740012984264378178+0x61/0xd0
   device_release+0x4f/0x90
   kobject_put+0x95/0x180
   nvme_put_ns+0x23/0xc0
   nvme_remove_invalid_namespaces+0xb3/0xd0
   nvme_scan_work+0x342/0x490
   process_scheduled_works+0x1a2/0x370
   worker_thread+0x2ff/0x390
   ? pwq_release_workfn+0x1e0/0x1e0
   kthread+0xb1/0xe0
   ? __kthread_parkme+0x70/0x70
   ret_from_fork+0x30/0x40
   ? __kthread_parkme+0x70/0x70
   ret_from_fork_asm+0x11/0x20
   </TASK>
  ---[ end trace 0000000000000000 ]---
<snip>

To address this switch to use of independent WQ_MEM_RECLAIM
workqueue, so the rules are not violated from workqueue framework
point of view.

Apart of that, since kvfree_rcu() does reclaim memory it is worth
to go with WQ_MEM_RECLAIM type of wq because it is designed for
this purpose.

Fixes: 6c6c47b063 ("mm, slab: call kvfree_rcu_barrier() from kmem_cache_destroy()"),
Reported-by: Keith Busch <kbusch@kernel.org>
Closes: https://lore.kernel.org/all/Z7iqJtCjHKfo8Kho@kbusch-mbp/
Cc: stable@vger.kernel.org
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-03-04 08:51:53 +01:00
Nam Cao
53867760f5 mm/slab: Switch to use hrtimer_setup()
hrtimer_setup() takes the callback function pointer as argument and
initializes the timer completely.

Replace hrtimer_init() and the open coded initialization of
hrtimer::function with the new setup mechanism.

Patch was created by using Coccinelle.

Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/all/030065d66630068f788caf9df15756fad404e754.1738746821.git.namcao@linutronix.de
2025-02-18 10:32:32 +01:00
Vlastimil Babka
c9f8f1242a slab: don't batch kvfree_rcu() with SLUB_TINY
kvfree_rcu() is batched for better performance except on TINY_RCU, which
is a simple implementation for small UP systems. Similarly SLUB_TINY is
an option intended for small systems, whether or not used together with
TINY_RCU. In case SLUB_TINY is used with !TINY_RCU, it makes arguably
sense to not do the batching and limit the memory footprint. It's also
suboptimal to have RCU-specific #ifdefs in slab code.

With that, add CONFIG_KVFREE_RCU_BATCHED to determine whether batching
kvfree_rcu() implementation is used. It is not set by a user prompt, but
enabled by default and disabled in case TINY_RCU or SLUB_TINY are
enabled.

Use the new config for #ifdef's in slab code and extend their scope to
cover all code used by the batched kvfree_rcu(). For example there's no
need to perform kvfree_rcu_init() if the batching is disabled.

Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-02-05 10:45:35 +01:00
Vlastimil Babka
49d5377b38 rcu, slab: use a regular callback function for kvfree_rcu
RCU has been special-casing callback function pointers that are integers
lower than 4096 as offsets of rcu_head for kvfree() instead. The tree
RCU implementation no longer does that as the batched kvfree_rcu() is
not a simple call_rcu(). The tiny RCU still does, and the plan is also
to make tree RCU use call_rcu() for SLUB_TINY configurations.

Instead of teaching tree RCU again to special case the offsets, let's
remove the special casing completely. Since there's no SLOB anymore, it
is possible to create a callback function that can take a pointer to a
middle of slab object with unknown offset and determine the object's
pointer before freeing it, so implement that as kvfree_rcu_cb().

Large kmalloc and vmalloc allocations are handled simply by aligning
down to page size. For that we retain the requirement that the offset is
smaller than 4096. But we can remove __is_kvfree_rcu_offset() completely
and instead just opencode the condition in the BUILD_BUG_ON() check.

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-02-05 10:45:29 +01:00
Vlastimil Babka
b14ff274e8 slab, rcu: move TINY_RCU variant of kvfree_rcu() to SLAB
Following the move of TREE_RCU implementation, let's move also the
TINY_RCU one for consistency and subsequent refactoring.

For simplicity, remove the separate inline __kvfree_call_rcu() as
TINY_RCU is not meant for high-performance hardware anyway.

Declare kvfree_call_rcu() in rcupdate.h to avoid header dependency
issues.

Also move the kvfree_rcu_barrier() declaration to slab.h

Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-02-05 10:45:12 +01:00
Linus Torvalds
9c5968db9e The various patchsets are summarized below. Plus of course many
indivudual patches which are described in their changelogs.
 
 - "Allocate and free frozen pages" from Matthew Wilcox reorganizes the
   page allocator so we end up with the ability to allocate and free
   zero-refcount pages.  So that callers (ie, slab) can avoid a refcount
   inc & dec.
 
 - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to use
   large folios other than PMD-sized ones.
 
 - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance and
   fixes for this small built-in kernel selftest.
 
 - "mas_anode_descend() related cleanup" from Wei Yang tidies up part of
   the mapletree code.
 
 - "mm: fix format issues and param types" from Keren Sun implements a
   few minor code cleanups.
 
 - "simplify split calculation" from Wei Yang provides a few fixes and a
   test for the mapletree code.
 
 - "mm/vma: make more mmap logic userland testable" from Lorenzo Stoakes
   continues the work of moving vma-related code into the (relatively) new
   mm/vma.c.
 
 - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
   Hildenbrand cleans up and rationalizes handling of gfp flags in the page
   allocator.
 
 - "readahead: Reintroduce fix for improper RA window sizing" from Jan
   Kara is a second attempt at fixing a readahead window sizing issue.  It
   should reduce the amount of unnecessary reading.
 
 - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
   addresses an issue where "huge" amounts of pte pagetables are
   accumulated
   (https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/).
   Qi's series addresses this windup by synchronously freeing PTE memory
   within the context of madvise(MADV_DONTNEED).
 
 - "selftest/mm: Remove warnings found by adding compiler flags" from
   Muhammad Usama Anjum fixes some build warnings in the selftests code
   when optional compiler warnings are enabled.
 
 - "mm: don't use __GFP_HARDWALL when migrating remote pages" from David
   Hildenbrand tightens the allocator's observance of __GFP_HARDWALL.
 
 - "pkeys kselftests improvements" from Kevin Brodsky implements various
   fixes and cleanups in the MM selftests code, mainly pertaining to the
   pkeys tests.
 
 - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
   estimate application working set size.
 
 - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
   provides some cleanups to memcg's hugetlb charging logic.
 
 - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
   removes the global swap cgroup lock.  A speedup of 10% for a tmpfs-based
   kernel build was demonstrated.
 
 - "zram: split page type read/write handling" from Sergey Senozhatsky
   has several fixes and cleaups for zram in the area of zram_write_page().
   A watchdog softlockup warning was eliminated.
 
 - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin Brodsky
   cleans up the pagetable destructor implementations.  A rare
   use-after-free race is fixed.
 
 - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
   simplifies and cleans up the debugging code in the VMA merging logic.
 
 - "Account page tables at all levels" from Kevin Brodsky cleans up and
   regularizes the pagetable ctor/dtor handling.  This results in
   improvements in accounting accuracy.
 
 - "mm/damon: replace most damon_callback usages in sysfs with new core
   functions" from SeongJae Park cleans up and generalizes DAMON's sysfs
   file interface logic.
 
 - "mm/damon: enable page level properties based monitoring" from
   SeongJae Park increases the amount of information which is presented in
   response to DAMOS actions.
 
 - "mm/damon: remove DAMON debugfs interface" from SeongJae Park removes
   DAMON's long-deprecated debugfs interfaces.  Thus the migration to sysfs
   is completed.
 
 - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from Peter
   Xu cleans up and generalizes the hugetlb reservation accounting.
 
 - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
   removes a never-used feature of the alloc_pages_bulk() interface.
 
 - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
   extends DAMOS filters to support not only exclusion (rejecting), but
   also inclusion (allowing) behavior.
 
 - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
   "introduces a new memory descriptor for zswap.zpool that currently
   overlaps with struct page for now.  This is part of the effort to reduce
   the size of struct page and to enable dynamic allocation of memory
   descriptors."
 
 - "mm, swap: rework of swap allocator locks" from Kairui Song redoes and
   simplifies the swap allocator locking.  A speedup of 400% was
   demonstrated for one workload.  As was a 35% reduction for kernel build
   time with swap-on-zram.
 
 - "mm: update mips to use do_mmap(), make mmap_region() internal" from
   Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
   mmap_region() can be made MM-internal.
 
 - "mm/mglru: performance optimizations" from Yu Zhao fixes a few MGLRU
   regressions and otherwise improves MGLRU performance.
 
 - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae Park
   updates DAMON documentation.
 
 - "Cleanup for memfd_create()" from Isaac Manjarres does that thing.
 
 - "mm: hugetlb+THP folio and migration cleanups" from David Hildenbrand
   provides various cleanups in the areas of hugetlb folios, THP folios and
   migration.
 
 - "Uncached buffered IO" from Jens Axboe implements the new
   RWF_DONTCACHE flag which provides synchronous dropbehind for pagecache
   reading and writing.  To permite userspace to address issues with
   massive buildup of useless pagecache when reading/writing fast devices.
 
 - "selftests/mm: virtual_address_range: Reduce memory" from Thomas
   Weißschuh fixes and optimizes some of the MM selftests.
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Merge tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "The various patchsets are summarized below. Plus of course many
  indivudual patches which are described in their changelogs.

   - "Allocate and free frozen pages" from Matthew Wilcox reorganizes
     the page allocator so we end up with the ability to allocate and
     free zero-refcount pages. So that callers (ie, slab) can avoid a
     refcount inc & dec

   - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to
     use large folios other than PMD-sized ones

   - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance
     and fixes for this small built-in kernel selftest

   - "mas_anode_descend() related cleanup" from Wei Yang tidies up part
     of the mapletree code

   - "mm: fix format issues and param types" from Keren Sun implements a
     few minor code cleanups

   - "simplify split calculation" from Wei Yang provides a few fixes and
     a test for the mapletree code

   - "mm/vma: make more mmap logic userland testable" from Lorenzo
     Stoakes continues the work of moving vma-related code into the
     (relatively) new mm/vma.c

   - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
     Hildenbrand cleans up and rationalizes handling of gfp flags in the
     page allocator

   - "readahead: Reintroduce fix for improper RA window sizing" from Jan
     Kara is a second attempt at fixing a readahead window sizing issue.
     It should reduce the amount of unnecessary reading

   - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
     addresses an issue where "huge" amounts of pte pagetables are
     accumulated:

       https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/

     Qi's series addresses this windup by synchronously freeing PTE
     memory within the context of madvise(MADV_DONTNEED)

   - "selftest/mm: Remove warnings found by adding compiler flags" from
     Muhammad Usama Anjum fixes some build warnings in the selftests
     code when optional compiler warnings are enabled

   - "mm: don't use __GFP_HARDWALL when migrating remote pages" from
     David Hildenbrand tightens the allocator's observance of
     __GFP_HARDWALL

   - "pkeys kselftests improvements" from Kevin Brodsky implements
     various fixes and cleanups in the MM selftests code, mainly
     pertaining to the pkeys tests

   - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
     estimate application working set size

   - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
     provides some cleanups to memcg's hugetlb charging logic

   - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
     removes the global swap cgroup lock. A speedup of 10% for a
     tmpfs-based kernel build was demonstrated

   - "zram: split page type read/write handling" from Sergey Senozhatsky
     has several fixes and cleaups for zram in the area of
     zram_write_page(). A watchdog softlockup warning was eliminated

   - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin
     Brodsky cleans up the pagetable destructor implementations. A rare
     use-after-free race is fixed

   - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
     simplifies and cleans up the debugging code in the VMA merging
     logic

   - "Account page tables at all levels" from Kevin Brodsky cleans up
     and regularizes the pagetable ctor/dtor handling. This results in
     improvements in accounting accuracy

   - "mm/damon: replace most damon_callback usages in sysfs with new
     core functions" from SeongJae Park cleans up and generalizes
     DAMON's sysfs file interface logic

   - "mm/damon: enable page level properties based monitoring" from
     SeongJae Park increases the amount of information which is
     presented in response to DAMOS actions

   - "mm/damon: remove DAMON debugfs interface" from SeongJae Park
     removes DAMON's long-deprecated debugfs interfaces. Thus the
     migration to sysfs is completed

   - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from
     Peter Xu cleans up and generalizes the hugetlb reservation
     accounting

   - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
     removes a never-used feature of the alloc_pages_bulk() interface

   - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
     extends DAMOS filters to support not only exclusion (rejecting),
     but also inclusion (allowing) behavior

   - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
     introduces a new memory descriptor for zswap.zpool that currently
     overlaps with struct page for now. This is part of the effort to
     reduce the size of struct page and to enable dynamic allocation of
     memory descriptors

   - "mm, swap: rework of swap allocator locks" from Kairui Song redoes
     and simplifies the swap allocator locking. A speedup of 400% was
     demonstrated for one workload. As was a 35% reduction for kernel
     build time with swap-on-zram

   - "mm: update mips to use do_mmap(), make mmap_region() internal"
     from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
     mmap_region() can be made MM-internal

   - "mm/mglru: performance optimizations" from Yu Zhao fixes a few
     MGLRU regressions and otherwise improves MGLRU performance

   - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae
     Park updates DAMON documentation

   - "Cleanup for memfd_create()" from Isaac Manjarres does that thing

   - "mm: hugetlb+THP folio and migration cleanups" from David
     Hildenbrand provides various cleanups in the areas of hugetlb
     folios, THP folios and migration

   - "Uncached buffered IO" from Jens Axboe implements the new
     RWF_DONTCACHE flag which provides synchronous dropbehind for
     pagecache reading and writing. To permite userspace to address
     issues with massive buildup of useless pagecache when
     reading/writing fast devices

   - "selftests/mm: virtual_address_range: Reduce memory" from Thomas
     Weißschuh fixes and optimizes some of the MM selftests"

* tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
  mm/compaction: fix UBSAN shift-out-of-bounds warning
  s390/mm: add missing ctor/dtor on page table upgrade
  kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags()
  tools: add VM_WARN_ON_VMG definition
  mm/damon/core: use str_high_low() helper in damos_wmark_wait_us()
  seqlock: add missing parameter documentation for raw_seqcount_try_begin()
  mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh
  mm/page_alloc: remove the incorrect and misleading comment
  zram: remove zcomp_stream_put() from write_incompressible_page()
  mm: separate move/undo parts from migrate_pages_batch()
  mm/kfence: use str_write_read() helper in get_access_type()
  selftests/mm/mkdirty: fix memory leak in test_uffdio_copy()
  kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags()
  selftests/mm: virtual_address_range: avoid reading from VM_IO mappings
  selftests/mm: vm_util: split up /proc/self/smaps parsing
  selftests/mm: virtual_address_range: unmap chunks after validation
  selftests/mm: virtual_address_range: mmap() without PROT_WRITE
  selftests/memfd/memfd_test: fix possible NULL pointer dereference
  mm: add FGP_DONTCACHE folio creation flag
  mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue
  ...
2025-01-26 18:36:23 -08:00
Uladzislau Rezki (Sony)
bbe658d658 mm/slab: Move kvfree_rcu() into SLAB
Move kvfree_rcu() functionality to the slab_common.c file.

The reason to have kvfree_rcu() functionality as part of SLAB is that
there is a clear trend and need of closer integration. One of the recent
example is creating a barrier function for SLAB caches.

Another reason is to prevent of having several implementations of RCU
machinery for reclaiming objects after a GP. As future steps, it can be
more integrated(easier) with SLAB internals.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: Hyeonggon Yoo <hyeonggon.yoo@sk.com>
Tested-by: Hyeonggon Yoo <hyeonggon.yoo@sk.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2025-01-11 20:39:43 +01:00
Linus Torvalds
e06635e26c slab updates for 6.13
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Merge tag 'slab-for-6.13-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

Pull slab updates from Vlastimil Babka:

 - Add new slab_strict_numa boot parameter to enforce per-object memory
   policies on top of slab folio policies, for systems where saving cost
   of remote accesses is more important than minimizing slab allocation
   overhead (Christoph Lameter)

 - Fix for freeptr_offset alignment check being too strict for m68k
   (Geert Uytterhoeven)

 - krealloc() fixes for not violating __GFP_ZERO guarantees on
   krealloc() when slub_debug (redzone and object tracking) is enabled
   (Feng Tang)

 - Fix a memory leak in case sysfs registration fails for a slab cache,
   and also no longer fail to create the cache in that case (Hyeonggon
   Yoo)

 - Fix handling of detected consistency problems (due to buggy slab
   user) with slub_debug enabled, so that it does not cause further list
   corruption bugs (yuan.gao)

 - Code cleanup and kerneldocs polishing (Zhen Lei, Vlastimil Babka)

* tag 'slab-for-6.13-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  slab: Fix too strict alignment check in create_cache()
  mm/slab: Allow cache creation to proceed even if sysfs registration fails
  mm/slub: Avoid list corruption when removing a slab from the full list
  mm/slub, kunit: Add testcase for krealloc redzone and zeroing
  mm/slub: Improve redzone check and zeroing for krealloc()
  mm/slub: Consider kfence case for get_orig_size()
  SLUB: Add support for per object memory policies
  mm, slab: add kerneldocs for common SLAB_ flags
  mm/slab: remove duplicate check in create_cache()
  mm/slub: Move krealloc() and related code to slub.c
  mm/kasan: Don't store metadata inside kmalloc object when slub_debug_orig_size is on
2024-11-25 16:51:24 -08:00
Geert Uytterhoeven
9008fe8fad slab: Fix too strict alignment check in create_cache()
On m68k, where the minimum alignment of unsigned long is 2 bytes:

    Kernel panic - not syncing: __kmem_cache_create_args: Failed to create slab 'io_kiocb'. Error -22
    CPU: 0 UID: 0 PID: 1 Comm: swapper Not tainted 6.12.0-atari-03776-g7eaa1f99261a #1783
    Stack from 0102fe5c:
	    0102fe5c 00514a2b 00514a2b ffffff00 00000001 0051f5ed 00425e78 00514a2b
	    0041eb74 ffffffea 00000310 0051f5ed ffffffea ffffffea 00601f60 00000044
	    0102ff20 000e7a68 0051ab8e 004383b8 0051f5ed ffffffea 000000b8 00000007
	    01020c00 00000000 000e77f0 0041e5f0 005f67c0 0051f5ed 000000b6 0102fef4
	    00000310 0102fef4 00000000 00000016 005f676c 0060a34c 00000010 00000004
	    00000038 0000009a 01000000 000000b8 005f668e 0102e000 00001372 0102ff88
    Call Trace: [<00425e78>] dump_stack+0xc/0x10
     [<0041eb74>] panic+0xd8/0x26c
     [<000e7a68>] __kmem_cache_create_args+0x278/0x2e8
     [<000e77f0>] __kmem_cache_create_args+0x0/0x2e8
     [<0041e5f0>] memset+0x0/0x8c
     [<005f67c0>] io_uring_init+0x54/0xd2

The minimal alignment of an integral type may differ from its size,
hence is not safe to assume that an arbitrary freeptr_t (which is
basically an unsigned long) is always aligned to 4 or 8 bytes.

As nothing seems to require the additional alignment, it is safe to fix
this by relaxing the check to the actual minimum alignment of freeptr_t.

Fixes: aaa736b186 ("io_uring: specify freeptr usage for SLAB_TYPESAFE_BY_RCU io_kiocb cache")
Fixes: d345bd2e98 ("mm: add kmem_cache_create_rcu()")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Closes: https://lore.kernel.org/37c588d4-2c32-4aad-a19e-642961f200d7@roeck-us.net
Cc: <stable@vger.kernel.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-11-20 19:15:47 +01:00
Alexei Starovoitov
8714381703 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Cross-merge bpf fixes after downstream PR.

In particular to bring the fix in
commit aa30eb3260 ("bpf: Force checkpoint when jmp history is too long").
The follow up verifier work depends on it.
And the fix in
commit 6801cf7890 ("selftests/bpf: Use -4095 as the bad address for bits iterator").
It's fixing instability of BPF CI on s390 arch.

No conflicts.

Adjacent changes in:
Auto-merging arch/Kconfig
Auto-merging kernel/bpf/helpers.c
Auto-merging kernel/bpf/memalloc.c
Auto-merging kernel/bpf/verifier.c
Auto-merging mm/slab_common.c

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-13 12:52:51 -08:00
Koichiro Den
9c9201afeb mm/slab: fix warning caused by duplicate kmem_cache creation in kmem_buckets_create
Commit b035f5a6d8 ("mm: slab: reduce the kmalloc() minimum alignment
if DMA bouncing possible") reduced ARCH_KMALLOC_MINALIGN to 8 on arm64.
However, with KASAN_HW_TAGS enabled, arch_slab_minalign() becomes 16.
This causes kmalloc_caches[*][8] to be aliased to kmalloc_caches[*][16],
resulting in kmem_buckets_create() attempting to create a kmem_cache for
size 16 twice. This duplication triggers warnings on boot:

[    2.325108] ------------[ cut here ]------------
[    2.325135] kmem_cache of name 'memdup_user-16' already exists
[    2.325783] WARNING: CPU: 0 PID: 1 at mm/slab_common.c:107 __kmem_cache_create_args+0xb8/0x3b0
[    2.327957] Modules linked in:
[    2.328550] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.0-rc5mm-unstable-arm64+ #12
[    2.328683] Hardware name: QEMU QEMU Virtual Machine, BIOS 2024.02-2 03/11/2024
[    2.328790] pstate: 61000009 (nZCv daif -PAN -UAO -TCO +DIT -SSBS BTYPE=--)
[    2.328911] pc : __kmem_cache_create_args+0xb8/0x3b0
[    2.328930] lr : __kmem_cache_create_args+0xb8/0x3b0
[    2.328942] sp : ffff800083d6fc50
[    2.328961] x29: ffff800083d6fc50 x28: f2ff0000c1674410 x27: ffff8000820b0598
[    2.329061] x26: 000000007fffffff x25: 0000000000000010 x24: 0000000000002000
[    2.329101] x23: ffff800083d6fce8 x22: ffff8000832222e8 x21: ffff800083222388
[    2.329118] x20: f2ff0000c1674410 x19: f5ff0000c16364c0 x18: ffff800083d80030
[    2.329135] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
[    2.329152] x14: 0000000000000000 x13: 0a73747369786520 x12: 79646165726c6120
[    2.329169] x11: 656820747563205b x10: 2d2d2d2d2d2d2d2d x9 : 0000000000000000
[    2.329194] x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
[    2.329210] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000
[    2.329226] x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000
[    2.329291] Call trace:
[    2.329407]  __kmem_cache_create_args+0xb8/0x3b0
[    2.329499]  kmem_buckets_create+0xfc/0x320
[    2.329526]  init_user_buckets+0x34/0x78
[    2.329540]  do_one_initcall+0x64/0x3c8
[    2.329550]  kernel_init_freeable+0x26c/0x578
[    2.329562]  kernel_init+0x3c/0x258
[    2.329574]  ret_from_fork+0x10/0x20
[    2.329698] ---[ end trace 0000000000000000 ]---

[    2.403704] ------------[ cut here ]------------
[    2.404716] kmem_cache of name 'msg_msg-16' already exists
[    2.404801] WARNING: CPU: 2 PID: 1 at mm/slab_common.c:107 __kmem_cache_create_args+0xb8/0x3b0
[    2.404842] Modules linked in:
[    2.404971] CPU: 2 UID: 0 PID: 1 Comm: swapper/0 Tainted: G        W          6.12.0-rc5mm-unstable-arm64+ #12
[    2.405026] Tainted: [W]=WARN
[    2.405043] Hardware name: QEMU QEMU Virtual Machine, BIOS 2024.02-2 03/11/2024
[    2.405057] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[    2.405079] pc : __kmem_cache_create_args+0xb8/0x3b0
[    2.405100] lr : __kmem_cache_create_args+0xb8/0x3b0
[    2.405111] sp : ffff800083d6fc50
[    2.405115] x29: ffff800083d6fc50 x28: fbff0000c1674410 x27: ffff8000820b0598
[    2.405135] x26: 000000000000ffd0 x25: 0000000000000010 x24: 0000000000006000
[    2.405153] x23: ffff800083d6fce8 x22: ffff8000832222e8 x21: ffff800083222388
[    2.405169] x20: fbff0000c1674410 x19: fdff0000c163d6c0 x18: ffff800083d80030
[    2.405185] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
[    2.405201] x14: 0000000000000000 x13: 0a73747369786520 x12: 79646165726c6120
[    2.405217] x11: 656820747563205b x10: 2d2d2d2d2d2d2d2d x9 : 0000000000000000
[    2.405233] x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
[    2.405248] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000
[    2.405271] x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000
[    2.405287] Call trace:
[    2.405293]  __kmem_cache_create_args+0xb8/0x3b0
[    2.405305]  kmem_buckets_create+0xfc/0x320
[    2.405315]  init_msg_buckets+0x34/0x78
[    2.405326]  do_one_initcall+0x64/0x3c8
[    2.405337]  kernel_init_freeable+0x26c/0x578
[    2.405348]  kernel_init+0x3c/0x258
[    2.405360]  ret_from_fork+0x10/0x20
[    2.405370] ---[ end trace 0000000000000000 ]---

To address this, alias kmem_cache for sizes smaller than min alignment
to the aligned sized kmem_cache, as done with the default system kmalloc
bucket.

Fixes: b32801d125 ("mm/slab: Introduce kmem_buckets_create() and family")
Cc: <stable@vger.kernel.org> # v6.11+
Signed-off-by: Koichiro Den <koichiro.den@gmail.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-11-05 17:26:27 +01:00
Vlastimil Babka
b6da940130 mm, slab: add kerneldocs for common SLAB_ flags
We have many SLAB_ flags but many are used only internally, by kunit
tests or debugging subsystems cooperating with slab, or are set
according to slab_debug boot parameter.

Create kerneldocs for the commonly used flags that may be passed to
kmem_cache_create(). SLAB_TYPESAFE_BY_RCU already had a detailed
description, so turn it to a kerneldoc. Add some details for
SLAB_ACCOUNT, SLAB_RECLAIM_ACCOUNT and SLAB_HWCACHE_ALIGN. Reference
them from the __kmem_cache_create_args() kerneldoc.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-10-29 10:43:24 +01:00
Zhen Lei
b4b797d877 mm/slab: remove duplicate check in create_cache()
The WARN_ON() check in static function create_cache() is done by its only
parent __kmem_cache_create_args() before calling it.
	if (... ||
	    WARN_ON(... ||
		    object_size - args->usersize < args->useroffset))
		args->usersize = args->useroffset = 0;
	...
	s = create_cache(cache_name, object_size, args, flags);

Therefore, the WARN_ON() check in create_cache() can be safely removed.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-10-29 10:43:24 +01:00
Feng Tang
1e4df1859e mm/slub: Move krealloc() and related code to slub.c
This is a preparation for the following refactoring of krealloc(),
for more efficient function calling as it will call some internal
functions defined in slub.c.

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-10-29 10:43:23 +01:00
Qun-Wei Lin
704573851b mm: krealloc: Fix MTE false alarm in __do_krealloc
This patch addresses an issue introduced by commit 1a83a716ec ("mm:
krealloc: consider spare memory for __GFP_ZERO") which causes MTE
(Memory Tagging Extension) to falsely report a slab-out-of-bounds error.

The problem occurs when zeroing out spare memory in __do_krealloc. The
original code only considered software-based KASAN and did not account
for MTE. It does not reset the KASAN tag before calling memset, leading
to a mismatch between the pointer tag and the memory tag, resulting
in a false positive.

Example of the error:
==================================================================
swapper/0: BUG: KASAN: slab-out-of-bounds in __memset+0x84/0x188
swapper/0: Write at addr f4ffff8005f0fdf0 by task swapper/0/1
swapper/0: Pointer tag: [f4], memory tag: [fe]
swapper/0:
swapper/0: CPU: 4 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.
swapper/0: Hardware name: MT6991(ENG) (DT)
swapper/0: Call trace:
swapper/0:  dump_backtrace+0xfc/0x17c
swapper/0:  show_stack+0x18/0x28
swapper/0:  dump_stack_lvl+0x40/0xa0
swapper/0:  print_report+0x1b8/0x71c
swapper/0:  kasan_report+0xec/0x14c
swapper/0:  __do_kernel_fault+0x60/0x29c
swapper/0:  do_bad_area+0x30/0xdc
swapper/0:  do_tag_check_fault+0x20/0x34
swapper/0:  do_mem_abort+0x58/0x104
swapper/0:  el1_abort+0x3c/0x5c
swapper/0:  el1h_64_sync_handler+0x80/0xcc
swapper/0:  el1h_64_sync+0x68/0x6c
swapper/0:  __memset+0x84/0x188
swapper/0:  btf_populate_kfunc_set+0x280/0x3d8
swapper/0:  __register_btf_kfunc_id_set+0x43c/0x468
swapper/0:  register_btf_kfunc_id_set+0x48/0x60
swapper/0:  register_nf_nat_bpf+0x1c/0x40
swapper/0:  nf_nat_init+0xc0/0x128
swapper/0:  do_one_initcall+0x184/0x464
swapper/0:  do_initcall_level+0xdc/0x1b0
swapper/0:  do_initcalls+0x70/0xc0
swapper/0:  do_basic_setup+0x1c/0x28
swapper/0:  kernel_init_freeable+0x144/0x1b8
swapper/0:  kernel_init+0x20/0x1a8
swapper/0:  ret_from_fork+0x10/0x20
==================================================================

Fixes: 1a83a716ec ("mm: krealloc: consider spare memory for __GFP_ZERO")
Signed-off-by: Qun-Wei Lin <qun-wei.lin@mediatek.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-10-29 10:40:53 +01:00
Alexei Starovoitov
bfa7b5c98b Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Cross-merge bpf fixes after downstream PR.

No conflicts.

Adjacent changes in:

include/linux/bpf.h
include/uapi/linux/bpf.h
kernel/bpf/btf.c
kernel/bpf/helpers.c
kernel/bpf/syscall.c
kernel/bpf/verifier.c
kernel/trace/bpf_trace.c
mm/slab_common.c
tools/include/uapi/linux/bpf.h
tools/testing/selftests/bpf/Makefile

Link: https://lore.kernel.org/all/20241024215724.60017-1-daniel@iogearbox.net/
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-24 18:47:28 -07:00
Namhyung Kim
a992d7a397 mm/bpf: Add bpf_get_kmem_cache() kfunc
The bpf_get_kmem_cache() is to get a slab cache information from a
virtual address like virt_to_cache().  If the address is a pointer
to a slab object, it'd return a valid kmem_cache pointer, otherwise
NULL is returned.

It doesn't grab a reference count of the kmem_cache so the caller is
responsible to manage the access.  The returned point is marked as
PTR_UNTRUSTED.

The intended use case for now is to symbolize locks in slab objects
from the lock contention tracepoints.

Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev> (mm/*)
Acked-by: Vlastimil Babka <vbabka@suse.cz> #mm/slab
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241010232505.1339892-3-namhyung@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-16 09:21:03 -07:00
Vlastimil Babka
3f1dd33f99 mm, slab: suppress warnings in test_leak_destroy kunit test
The test_leak_destroy kunit test intends to test the detection of stray
objects in kmem_cache_destroy(), which normally produces a warning. The
other slab kunit tests suppress the warnings in the kunit test context,
so suppress warnings and related printk output in this test as well.
Automated test running environments then don't need to learn to filter
the warnings.

Also rename the test's kmem_cache, the name was wrongly copy-pasted from
test_kfree_rcu.

Fixes: 4e1c44b3db ("kunit, slub: add test_kfree_rcu() and test_leak_destroy()")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202408251723.42f3d902-oliver.sang@intel.com
Reported-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Closes: https://lore.kernel.org/all/CAB=+i9RHHbfSkmUuLshXGY_ifEZg9vCZi3fqr99+kmmnpDus7Q@mail.gmail.com/
Reported-by: Guenter Roeck <linux@roeck-us.net>
Closes: https://lore.kernel.org/all/6fcb1252-7990-4f0d-8027-5e83f0fb9409@roeck-us.net/
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-10-02 16:28:46 +02:00
Linus Torvalds
617a814f14 ALong with the usual shower of singleton patches, notable patch series in
this pull request are:
 
 "Align kvrealloc() with krealloc()" from Danilo Krummrich.  Adds
 consistency to the APIs and behaviour of these two core allocation
 functions.  This also simplifies/enables Rustification.
 
 "Some cleanups for shmem" from Baolin Wang.  No functional changes - mode
 code reuse, better function naming, logic simplifications.
 
 "mm: some small page fault cleanups" from Josef Bacik.  No functional
 changes - code cleanups only.
 
 "Various memory tiering fixes" from Zi Yan.  A small fix and a little
 cleanup.
 
 "mm/swap: remove boilerplate" from Yu Zhao.  Code cleanups and
 simplifications and .text shrinkage.
 
 "Kernel stack usage histogram" from Pasha Tatashin and Shakeel Butt.  This
 is a feature, it adds new feilds to /proc/vmstat such as
 
     $ grep kstack /proc/vmstat
     kstack_1k 3
     kstack_2k 188
     kstack_4k 11391
     kstack_8k 243
     kstack_16k 0
 
 which tells us that 11391 processes used 4k of stack while none at all
 used 16k.  Useful for some system tuning things, but partivularly useful
 for "the dynamic kernel stack project".
 
 "kmemleak: support for percpu memory leak detect" from Pavel Tikhomirov.
 Teaches kmemleak to detect leaksage of percpu memory.
 
 "mm: memcg: page counters optimizations" from Roman Gushchin.  "3
 independent small optimizations of page counters".
 
 "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from David
 Hildenbrand.  Improves PTE/PMD splitlock detection, makes powerpc/8xx work
 correctly by design rather than by accident.
 
 "mm: remove arch_make_page_accessible()" from David Hildenbrand.  Some
 folio conversions which make arch_make_page_accessible() unneeded.
 
 "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David Finkel.
 Cleans up and fixes our handling of the resetting of the cgroup/process
 peak-memory-use detector.
 
 "Make core VMA operations internal and testable" from Lorenzo Stoakes.
 Rationalizaion and encapsulation of the VMA manipulation APIs.  With a
 view to better enable testing of the VMA functions, even from a
 userspace-only harness.
 
 "mm: zswap: fixes for global shrinker" from Takero Funaki.  Fix issues in
 the zswap global shrinker, resulting in improved performance.
 
 "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao.  Fill in
 some missing info in /proc/zoneinfo.
 
 "mm: replace follow_page() by folio_walk" from David Hildenbrand.  Code
 cleanups and rationalizations (conversion to folio_walk()) resulting in
 the removal of follow_page().
 
 "improving dynamic zswap shrinker protection scheme" from Nhat Pham.  Some
 tuning to improve zswap's dynamic shrinker.  Significant reductions in
 swapin and improvements in performance are shown.
 
 "mm: Fix several issues with unaccepted memory" from Kirill Shutemov.
 Improvements to the new unaccepted memory feature,
 
 "mm/mprotect: Fix dax puds" from Peter Xu.  Implements mprotect on DAX
 PUDs.  This was missing, although nobody seems to have notied yet.
 
 "Introduce a store type enum for the Maple tree" from Sidhartha Kumar.
 Cleanups and modest performance improvements for the maple tree library
 code.
 
 "memcg: further decouple v1 code from v2" from Shakeel Butt.  Move more
 cgroup v1 remnants away from the v2 memcg code.
 
 "memcg: initiate deprecation of v1 features" from Shakeel Butt.  Adds
 various warnings telling users that memcg v1 features are deprecated.
 
 "mm: swap: mTHP swap allocator base on swap cluster order" from Chris Li.
 Greatly improves the success rate of the mTHP swap allocation.
 
 "mm: introduce numa_memblks" from Mike Rapoport.  Moves various disparate
 per-arch implementations of numa_memblk code into generic code.
 
 "mm: batch free swaps for zap_pte_range()" from Barry Song.  Greatly
 improves the performance of munmap() of swap-filled ptes.
 
 "support large folio swap-out and swap-in for shmem" from Baolin Wang.
 With this series we no longer split shmem large folios into simgle-page
 folios when swapping out shmem.
 
 "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao.  Nice performance
 improvements and code reductions for gigantic folios.
 
 "support shmem mTHP collapse" from Baolin Wang.  Adds support for
 khugepaged's collapsing of shmem mTHP folios.
 
 "mm: Optimize mseal checks" from Pedro Falcato.  Fixes an mprotect()
 performance regression due to the addition of mseal().
 
 "Increase the number of bits available in page_type" from Matthew Wilcox.
 Increases the number of bits available in page_type!
 
 "Simplify the page flags a little" from Matthew Wilcox.  Many legacy page
 flags are now folio flags, so the page-based flags and their
 accessors/mutators can be removed.
 
 "mm: store zero pages to be swapped out in a bitmap" from Usama Arif.  An
 optimization which permits us to avoid writing/reading zero-filled zswap
 pages to backing store.
 
 "Avoid MAP_FIXED gap exposure" from Liam Howlett.  Fixes a race window
 which occurs when a MAP_FIXED operqtion is occurring during an unrelated
 vma tree walk.
 
 "mm: remove vma_merge()" from Lorenzo Stoakes.  Major rotorooting of the
 vma_merge() functionality, making ot cleaner, more testable and better
 tested.
 
 "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.  Minor
 fixups of DAMON selftests and kunit tests.
 
 "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.  Code
 cleanups and folio conversions.
 
 "Shmem mTHP controls and stats improvements" from Ryan Roberts.  Cleanups
 for shmem controls and stats.
 
 "mm: count the number of anonymous THPs per size" from Barry Song.  Expose
 additional anon THP stats to userspace for improved tuning.
 
 "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more folio
 conversions and removal of now-unused page-based APIs.
 
 "replace per-quota region priorities histogram buffer with per-context
 one" from SeongJae Park.  DAMON histogram rationalization.
 
 "Docs/damon: update GitHub repo URLs and maintainer-profile" from SeongJae
 Park.  DAMON documentation updates.
 
 "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and improve
 related doc and warn" from Jason Wang: fixes usage of page allocator
 __GFP_NOFAIL and GFP_ATOMIC flags.
 
 "mm: split underused THPs" from Yu Zhao.  Improve THP=always policy - this
 was overprovisioning THPs in sparsely accessed memory areas.
 
 "zram: introduce custom comp backends API" frm Sergey Senozhatsky.  Add
 support for zram run-time compression algorithm tuning.
 
 "mm: Care about shadow stack guard gap when getting an unmapped area" from
 Mark Brown.  Fix up the various arch_get_unmapped_area() implementations
 to better respect guard areas.
 
 "Improve mem_cgroup_iter()" from Kinsey Ho.  Improve the reliability of
 mem_cgroup_iter() and various code cleanups.
 
 "mm: Support huge pfnmaps" from Peter Xu.  Extends the usage of huge
 pfnmap support.
 
 "resource: Fix region_intersects() vs add_memory_driver_managed()" from
 Huang Ying.  Fix a bug in region_intersects() for systems with CXL memory.
 
 "mm: hwpoison: two more poison recovery" from Kefeng Wang.  Teaches a
 couple more code paths to correctly recover from the encountering of
 poisoned memry.
 
 "mm: enable large folios swap-in support" from Barry Song.  Support the
 swapin of mTHP memory into appropriately-sized folios, rather than into
 single-page folios.
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Merge tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Along with the usual shower of singleton patches, notable patch series
  in this pull request are:

   - "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
     consistency to the APIs and behaviour of these two core allocation
     functions. This also simplifies/enables Rustification.

   - "Some cleanups for shmem" from Baolin Wang. No functional changes -
     mode code reuse, better function naming, logic simplifications.

   - "mm: some small page fault cleanups" from Josef Bacik. No
     functional changes - code cleanups only.

   - "Various memory tiering fixes" from Zi Yan. A small fix and a
     little cleanup.

   - "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
     simplifications and .text shrinkage.

   - "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
     Butt. This is a feature, it adds new feilds to /proc/vmstat such as

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

     which tells us that 11391 processes used 4k of stack while none at
     all used 16k. Useful for some system tuning things, but
     partivularly useful for "the dynamic kernel stack project".

   - "kmemleak: support for percpu memory leak detect" from Pavel
     Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.

   - "mm: memcg: page counters optimizations" from Roman Gushchin. "3
     independent small optimizations of page counters".

   - "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
     David Hildenbrand. Improves PTE/PMD splitlock detection, makes
     powerpc/8xx work correctly by design rather than by accident.

   - "mm: remove arch_make_page_accessible()" from David Hildenbrand.
     Some folio conversions which make arch_make_page_accessible()
     unneeded.

   - "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
     Finkel. Cleans up and fixes our handling of the resetting of the
     cgroup/process peak-memory-use detector.

   - "Make core VMA operations internal and testable" from Lorenzo
     Stoakes. Rationalizaion and encapsulation of the VMA manipulation
     APIs. With a view to better enable testing of the VMA functions,
     even from a userspace-only harness.

   - "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
     issues in the zswap global shrinker, resulting in improved
     performance.

   - "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
     in some missing info in /proc/zoneinfo.

   - "mm: replace follow_page() by folio_walk" from David Hildenbrand.
     Code cleanups and rationalizations (conversion to folio_walk())
     resulting in the removal of follow_page().

   - "improving dynamic zswap shrinker protection scheme" from Nhat
     Pham. Some tuning to improve zswap's dynamic shrinker. Significant
     reductions in swapin and improvements in performance are shown.

   - "mm: Fix several issues with unaccepted memory" from Kirill
     Shutemov. Improvements to the new unaccepted memory feature,

   - "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
     DAX PUDs. This was missing, although nobody seems to have notied
     yet.

   - "Introduce a store type enum for the Maple tree" from Sidhartha
     Kumar. Cleanups and modest performance improvements for the maple
     tree library code.

   - "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
     more cgroup v1 remnants away from the v2 memcg code.

   - "memcg: initiate deprecation of v1 features" from Shakeel Butt.
     Adds various warnings telling users that memcg v1 features are
     deprecated.

   - "mm: swap: mTHP swap allocator base on swap cluster order" from
     Chris Li. Greatly improves the success rate of the mTHP swap
     allocation.

   - "mm: introduce numa_memblks" from Mike Rapoport. Moves various
     disparate per-arch implementations of numa_memblk code into generic
     code.

   - "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
     improves the performance of munmap() of swap-filled ptes.

   - "support large folio swap-out and swap-in for shmem" from Baolin
     Wang. With this series we no longer split shmem large folios into
     simgle-page folios when swapping out shmem.

   - "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
     performance improvements and code reductions for gigantic folios.

   - "support shmem mTHP collapse" from Baolin Wang. Adds support for
     khugepaged's collapsing of shmem mTHP folios.

   - "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
     performance regression due to the addition of mseal().

   - "Increase the number of bits available in page_type" from Matthew
     Wilcox. Increases the number of bits available in page_type!

   - "Simplify the page flags a little" from Matthew Wilcox. Many legacy
     page flags are now folio flags, so the page-based flags and their
     accessors/mutators can be removed.

   - "mm: store zero pages to be swapped out in a bitmap" from Usama
     Arif. An optimization which permits us to avoid writing/reading
     zero-filled zswap pages to backing store.

   - "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
     window which occurs when a MAP_FIXED operqtion is occurring during
     an unrelated vma tree walk.

   - "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
     the vma_merge() functionality, making ot cleaner, more testable and
     better tested.

   - "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
     Minor fixups of DAMON selftests and kunit tests.

   - "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
     Code cleanups and folio conversions.

   - "Shmem mTHP controls and stats improvements" from Ryan Roberts.
     Cleanups for shmem controls and stats.

   - "mm: count the number of anonymous THPs per size" from Barry Song.
     Expose additional anon THP stats to userspace for improved tuning.

   - "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
     folio conversions and removal of now-unused page-based APIs.

   - "replace per-quota region priorities histogram buffer with
     per-context one" from SeongJae Park. DAMON histogram
     rationalization.

   - "Docs/damon: update GitHub repo URLs and maintainer-profile" from
     SeongJae Park. DAMON documentation updates.

   - "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
     improve related doc and warn" from Jason Wang: fixes usage of page
     allocator __GFP_NOFAIL and GFP_ATOMIC flags.

   - "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
     This was overprovisioning THPs in sparsely accessed memory areas.

   - "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
     Add support for zram run-time compression algorithm tuning.

   - "mm: Care about shadow stack guard gap when getting an unmapped
     area" from Mark Brown. Fix up the various arch_get_unmapped_area()
     implementations to better respect guard areas.

   - "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
     of mem_cgroup_iter() and various code cleanups.

   - "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
     pfnmap support.

   - "resource: Fix region_intersects() vs add_memory_driver_managed()"
     from Huang Ying. Fix a bug in region_intersects() for systems with
     CXL memory.

   - "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
     a couple more code paths to correctly recover from the encountering
     of poisoned memry.

   - "mm: enable large folios swap-in support" from Barry Song. Support
     the swapin of mTHP memory into appropriately-sized folios, rather
     than into single-page folios"

* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
  zram: free secondary algorithms names
  uprobes: turn xol_area->pages[2] into xol_area->page
  uprobes: introduce the global struct vm_special_mapping xol_mapping
  Revert "uprobes: use vm_special_mapping close() functionality"
  mm: support large folios swap-in for sync io devices
  mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
  mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
  mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
  set_memory: add __must_check to generic stubs
  mm/vma: return the exact errno in vms_gather_munmap_vmas()
  memcg: cleanup with !CONFIG_MEMCG_V1
  mm/show_mem.c: report alloc tags in human readable units
  mm: support poison recovery from copy_present_page()
  mm: support poison recovery from do_cow_fault()
  resource, kunit: add test case for region_intersects()
  resource: make alloc_free_mem_region() works for iomem_resource
  mm: z3fold: deprecate CONFIG_Z3FOLD
  vfio/pci: implement huge_fault support
  mm/arm64: support large pfn mappings
  mm/x86: support large pfn mappings
  ...
2024-09-21 07:29:05 -07:00
Vlastimil Babka
ecc4d6af97 Merge branch 'slab/for-6.12/kmem_cache_args' into slab/for-next
Merge kmem_cache_create() refactoring by Christian Brauner.

Note this includes a merge of the vfs.file tree that contains the
prerequisity kmem_cache_create_rcu() work.
2024-09-13 11:13:03 +02:00
Vlastimil Babka
a715e94dbd Merge branch 'slab/for-6.12/rcu_barriers' into slab/for-next
Merge most of SLUB feature work for 6.12:

- Barrier for pending kfree_rcu() in kmem_cache_destroy() and associated
  refactoring of the destroy path (Vlastimil Babka)
- CONFIG_SLUB_RCU_DEBUG to allow KASAN catching UAF bugs in
  SLAB_TYPESAFE_BY_RCU caches (Jann Horn)
- kmem_cache_charge() for delayed kmemcg charging (Shakeel Butt)
2024-09-13 11:08:27 +02:00
Vlastimil Babka
4b7ff9ab98 mm, slab: restore kerneldoc for kmem_cache_create()
As kmem_cache_create() became a _Generic() wrapper macro, it currently
has no kerneldoc despite being the main API to use. Add it. Also adjust
kmem_cache_create_usercopy() kerneldoc to indicate it is now a legacy
wrapper.

Also expand the kerneldoc for struct kmem_cache_args, especially for the
freeptr_offset field, where important details were removed with the
removal of kmem_cache_create_rcu().

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Christian Brauner <brauner@kernel.org>
2024-09-13 11:05:01 +02:00
Christian Brauner
781aee7556 slab: make __kmem_cache_create() static inline
Make __kmem_cache_create() a static inline function.

Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-10 11:42:59 +02:00
Christian Brauner
0c9050b09c slab: make kmem_cache_create_usercopy() static inline
Make kmem_cache_create_usercopy() a static inline function.

Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-10 11:42:58 +02:00
Christian Brauner
3d453e60f1 slab: remove kmem_cache_create_rcu()
Now that we have ported all users of kmem_cache_create_rcu() to struct
kmem_cache_args the function is unused and can be removed.

Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-10 11:42:58 +02:00
Christian Brauner
b2e7456b5c slab: create kmem_cache_create() compatibility layer
Use _Generic() to create a compatibility layer that type switches on the
third argument to either call __kmem_cache_create() or
__kmem_cache_create_args(). If NULL is passed for the struct
kmem_cache_args argument use default args making porting for callers
that don't care about additional arguments easy.

Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-10 11:42:58 +02:00
Christian Brauner
3dbe2bad57 slab: pass struct kmem_cache_args to do_kmem_cache_create()
and initialize most things in do_kmem_cache_create(). In a follow-up
patch we'll remove rcu_freeptr_offset from struct kmem_cache.

Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-10 11:42:58 +02:00
Christian Brauner
34410a9060 slab: pass struct kmem_cache_args to create_cache()
Pass struct kmem_cache_args to create_cache() so that we can later
simplify further helpers.

Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-10 11:42:58 +02:00
Christian Brauner
1d3d7645d7 slab: port kmem_cache_create_usercopy() to struct kmem_cache_args
Port kmem_cache_create_usercopy() to struct kmem_cache_args and remove
the now unused do_kmem_cache_create_usercopy() helper.

Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-10 11:42:58 +02:00
Christian Brauner
9816c3c4e7 slab: port kmem_cache_create_rcu() to struct kmem_cache_args
Port kmem_cache_create_rcu() to struct kmem_cache_args.

Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-10 11:42:58 +02:00
Christian Brauner
f6cd98c940 slab: port kmem_cache_create() to struct kmem_cache_args
Port kmem_cache_create() to struct kmem_cache_args.

Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-10 11:42:57 +02:00
Christian Brauner
879fb3c274 slab: add struct kmem_cache_args
Currently we have multiple kmem_cache_create*() variants that take up to
seven separate parameters with one of the functions having to grow an
eigth parameter in the future to handle both usercopy and a custom
freelist pointer.

Add a struct kmem_cache_args structure and move less common parameters
into it. Core parameters such as name, object size, and flags continue
to be passed separately.

Add a new function __kmem_cache_create_args() that takes a struct
kmem_cache_args pointer and port do_kmem_cache_create_usercopy() over to
it.

In follow-up patches we will port the other kmem_cache_create*()
variants over to it as well.

Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-10 11:42:57 +02:00
Christian Brauner
53d3d21086 slab: s/__kmem_cache_create/do_kmem_cache_create/g
Free up reusing the double-underscore variant for follow-up patches.

Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-10 11:42:57 +02:00
Xavier
e02147cb70 mm/slab: Optimize the code logic in find_mergeable()
We can first assess the flags, if it's unmergeable, there's no need
to calculate the size and align.

Signed-off-by: Xavier <xavier_qy@163.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-09-05 14:42:23 +02:00
Danilo Krummrich
489a744e5f mm: krealloc: clarify valid usage of __GFP_ZERO
Properly document that if __GFP_ZERO logic is requested, callers must
ensure that, starting with the initial memory allocation, every subsequent
call to this API for the same memory allocation is flagged with
__GFP_ZERO.  Otherwise, it is possible that __GFP_ZERO is not fully
honored by this API.

Link: https://lkml.kernel.org/r/20240812223707.32049-2-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-03 21:15:37 -07:00
Danilo Krummrich
1a83a716ec mm: krealloc: consider spare memory for __GFP_ZERO
As long as krealloc() is called with __GFP_ZERO consistently, starting
with the initial memory allocation, __GFP_ZERO should be fully honored.

However, if for an existing allocation krealloc() is called with a
decreased size, it is not ensured that the spare portion the allocation is
zeroed.  Thus, if krealloc() is subsequently called with a larger size
again, __GFP_ZERO can't be fully honored, since we don't know the previous
size, but only the bucket size.

Example:

	buf = kzalloc(64, GFP_KERNEL);
	memset(buf, 0xff, 64);

	buf = krealloc(buf, 48, GFP_KERNEL | __GFP_ZERO);

	/* After this call the last 16 bytes are still 0xff. */
	buf = krealloc(buf, 64, GFP_KERNEL | __GFP_ZERO);

Fix this, by explicitly setting spare memory to zero, when shrinking an
allocation with __GFP_ZERO flag set or init_on_alloc enabled.

Link: https://lkml.kernel.org/r/20240812223707.32049-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-03 21:15:37 -07:00
R Sundar
0f389adb4b mm: Removed @freeptr_offset to prevent doc warning
Removed @freeptr_offset to fix below doc warning.
./mm/slab_common.c:385: warning: Excess function parameter 'freeptr_offset' description in 'kmem_cache_create_usercopy'

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202408292249.5oUpnCbS-lkp@intel.com/
Signed-off-by: R Sundar <prosunofficial@gmail.com>
Link: https://lore.kernel.org/r/20240902020555.11506-1-prosunofficial@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-09-02 10:54:56 +02:00
Christian Brauner
d345bd2e98 mm: add kmem_cache_create_rcu()
When a kmem cache is created with SLAB_TYPESAFE_BY_RCU the free pointer
must be located outside of the object because we don't know what part of
the memory can safely be overwritten as it may be needed to prevent
object recycling.

That has the consequence that SLAB_TYPESAFE_BY_RCU may end up adding a
new cacheline. This is the case for e.g., struct file. After having it
shrunk down by 40 bytes and having it fit in three cachelines we still
have SLAB_TYPESAFE_BY_RCU adding a fourth cacheline because it needs to
accommodate the free pointer.

Add a new kmem_cache_create_rcu() function that allows the caller to
specify an offset where the free pointer is supposed to be placed.

Link: https://lore.kernel.org/r/20240828-work-kmem_cache-rcu-v3-2-5460bc1f09f6@kernel.org
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-29 15:20:32 +02:00
Christian Brauner
e446f18e98 mm: remove unused argument from create_cache()
That root_cache argument is unused so remove it.

Link: https://lore.kernel.org/r/20240828-work-kmem_cache-rcu-v3-1-5460bc1f09f6@kernel.org
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-29 15:20:32 +02:00
Yan Zhen
3beb2fb681 mm, slab: use kmem_cache_free() to free from kmem_buckets_cache
In kmem_buckets_create(), the kmem_buckets object is allocated by
kmem_cache_alloc() from kmem_buckets_cache, but in the failure case,
it's freed by kfree(). This is not wrong, but using kmem_cache_free()
is the more common pattern, so use it.

Signed-off-by: Yan Zhen <yanzhen@vivo.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-08-27 16:57:35 +02:00
Jann Horn
b8c8ba73c6 slub: Introduce CONFIG_SLUB_RCU_DEBUG
Currently, KASAN is unable to catch use-after-free in SLAB_TYPESAFE_BY_RCU
slabs because use-after-free is allowed within the RCU grace period by
design.

Add a SLUB debugging feature which RCU-delays every individual
kmem_cache_free() before either actually freeing the object or handing it
off to KASAN, and change KASAN to poison freed objects as normal when this
option is enabled.

For now I've configured Kconfig.debug to default-enable this feature in the
KASAN GENERIC and SW_TAGS modes; I'm not enabling it by default in HW_TAGS
mode because I'm not sure if it might have unwanted performance degradation
effects there.

Note that this is mostly useful with KASAN in the quarantine-based GENERIC
mode; SLAB_TYPESAFE_BY_RCU slabs are basically always also slabs with a
->ctor, and KASAN's assign_tag() currently has to assign fixed tags for
those, reducing the effectiveness of SW_TAGS/HW_TAGS mode.
(A possible future extension of this work would be to also let SLUB call
the ->ctor() on every allocation instead of only when the slab page is
allocated; then tag-based modes would be able to assign new tags on every
reallocation.)

Tested-by: syzbot+263726e59eab6b442723@syzkaller.appspotmail.com
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Acked-by: Marco Elver <elver@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz> #slab
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-08-27 14:12:51 +02:00
Vlastimil Babka
6c6c47b063 mm, slab: call kvfree_rcu_barrier() from kmem_cache_destroy()
We would like to replace call_rcu() users with kfree_rcu() where the
existing callback is just a kmem_cache_free(). However this causes
issues when the cache can be destroyed (such as due to module unload).

Currently such modules should be issuing rcu_barrier() before
kmem_cache_destroy() to have their call_rcu() callbacks processed first.
This barrier is however not sufficient for kfree_rcu() in flight due
to the batching introduced by a35d16905e ("rcu: Add basic support for
kfree_rcu() batching").

This is not a problem for kmalloc caches which are never destroyed, but
since removing SLOB, kfree_rcu() is allowed also for any other cache,
that might be destroyed.

In order not to complicate the API, put the responsibility for handling
outstanding kfree_rcu() in kmem_cache_destroy() itself. Use the newly
introduced kvfree_rcu_barrier() to wait before destroying the cache.
This is similar to how we issue rcu_barrier() for SLAB_TYPESAFE_BY_RCU
caches, but has to be done earlier, as the latter only needs to wait for
the empty slab pages to finish freeing, and not objects from the slab.

Users of call_rcu() with arbitrary callbacks should still issue
rcu_barrier() before destroying the cache and unloading the module, as
kvfree_rcu_barrier() is not a superset of rcu_barrier() and the
callbacks may be invoking module code or performing other actions that
are necessary for a successful unload.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-08-27 14:12:51 +02:00
Vlastimil Babka
2eb14c1c27 mm, slab: reintroduce rcu_barrier() into kmem_cache_destroy()
There used to be a rcu_barrier() for SLAB_TYPESAFE_BY_RCU caches in
kmem_cache_destroy() until commit 657dc2f972 ("slab: remove
synchronous rcu_barrier() call in memcg cache release path") moved it to
an asynchronous work that finishes the destroying of such caches.

The motivation for that commit was the MEMCG_KMEM integration that at
the time created and removed clones of the global slab caches together
with their cgroups, and blocking cgroups removal was unwelcome. The
implementation later changed to per-object memcg tracking using a single
cache, so there should be no more need for a fast non-blocking
kmem_cache_destroy(), which is typically only done when a module is
unloaded etc.

Going back to synchronous barrier has the following advantages:

- simpler implementation
- it's easier to test the result of kmem_cache_destroy() in a kunit test

Thus effectively revert commit 657dc2f972. It is not a 1:1 revert as
the code has changed since. The main part is that kmem_cache_release(s)
is always called from kmem_cache_destroy(), but for SLAB_TYPESAFE_BY_RCU
caches there's a rcu_barrier() first.

Suggested-by: Mateusz Guzik <mjguzik@gmail.com>
Reviewed-by: Jann Horn <jannh@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-08-27 14:12:51 +02:00
Vlastimil Babka
f77d0cda4a mm, slab: move kfence_shutdown_cache() outside slab_mutex
kfence_shutdown_cache() is called under slab_mutex when the cache is
destroyed synchronously, and outside slab_mutex during the delayed
destruction of SLAB_TYPESAFE_BY_RCU caches.

It seems it should always be safe to call it outside of slab_mutex so we
can just move the call to kmem_cache_release(), which is called outside.

Reviewed-by: Jann Horn <jannh@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-08-27 14:12:51 +02:00
Vlastimil Babka
4ec10268ed mm, slab: unlink slabinfo, sysfs and debugfs immediately
kmem_cache_destroy() includes removing the associated sysfs and debugfs
directories, and the cache from the list of caches that appears in
/proc/slabinfo. Currently this might not happen immediately when:

- the cache is SLAB_TYPESAFE_BY_RCU and the cleanup is delayed,
  including the directores removal
- __kmem_cache_shutdown() fails due to outstanding objects - the
  directories remain indefinitely

When a cache is recreated with the same name, such as due to module
unload followed by a load, the directories will fail to be recreated for
the new instance of the cache due to the old directories being present.
The cache will also appear twice in /proc/slabinfo.

While we want to convert the SLAB_TYPESAFE_BY_RCU cleanup to be
synchronous again, the second point remains. So let's fix this first and
have the directories and slabinfo removed immediately in
kmem_cache_destroy() and regardless of __kmem_cache_shutdown() success.

This should not make debugging harder if __kmem_cache_shutdown() fails,
because a detailed report of outstanding objects is printed into dmesg
already due to the failure.

Also simplify kmem_cache_release() sysfs handling by using
__is_defined(SLAB_SUPPORTS_SYSFS).

Note the resulting code in kmem_cache_destroy() is a bit ugly but will
be further simplified - this is in order to make small bisectable steps.

Reviewed-by: Jann Horn <jannh@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-08-27 14:12:50 +02:00
Vlastimil Babka
b5959789e9 mm, slab: dissolve shutdown_cache() into its caller
There's only one caller of shutdown_cache() so move the code into it.
Preparatory patch for further changes, no functional change.

Reviewed-by: Jann Horn <jannh@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-08-27 14:12:50 +02:00