[GIT PULL] slab updates for 7.0

[GIT PULL] slab updates for 7.0

[Vlastimil Babka]

Hi Linus,

please pull the latest slab updates from:

  git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab.git tags/slab-for-7.0

Thanks,
Vlastimil

======================================

- The percpu sheaves caching layer was introduced as opt-in in 6.18 and now
  we enable it for all caches and remove the previous cpu (partial) slab
  caching mechanism. Besides the lower locking overhead and much more likely
  fastpath when freeing, this removes the rather complicated code related to
  the cpu slab lockless fastpaths (using this_cpu_try_cmpxchg128/64) and all
  its complications for PREEMPT_RT or kmalloc_nolock().
    
  The lockless slab freelist+counters update operation using
  try_cmpxchg128/64 remains and is crucial for freeing remote NUMA objects,
  and to allow flushing objects from sheaves to slabs mostly without the
  node list_lock. (Vlastimil Babka)

- Eliminate slabobj_ext metadata overhead when possible. Instead of using
  kmalloc() to allocate the array for memcg and/or allocation profiling tag
  pointers, use leftover space in a slab or per-object padding due to
  alignment. (Harry Yoo)

- Various followup improvements to the above. (Hao Li)

----------------------------------------------------------------
The following changes since commit 99a3e3a1cfc93b8fe318c0a3a5cfb01f1d4ad53c:

  slab: fix kmalloc_nolock() context check for PREEMPT_RT (2026-01-21 11:34:18 +0100)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab.git tags/slab-for-7.0

for you to fetch changes up to 815c8e35511d0b9a214e9f644983fe477af9d5cb:

  Merge branch 'slab/for-7.0/sheaves' into slab/for-next (2026-02-10 09:10:00 +0100)

----------------------------------------------------------------
slab updates for 7.0

----------------------------------------------------------------
Hao Li (3):
      slub: keep empty main sheaf as spare in __pcs_replace_empty_main()
      slub: clarify object field layout comments
      slub: let need_slab_obj_exts() return false if SLAB_NO_OBJ_EXT is set

Harry Yoo (13):
      mm/slab: fix false lockdep warning in __kfree_rcu_sheaf()
      mm/slab: factor out slab_args_unmergeable()
      mm/slab: avoid allocating slabobj_ext array from its own slab
      mm/slab: use unsigned long for orig_size to ensure proper metadata align
      mm/slab: allow specifying free pointer offset when using constructor
      ext4: specify the free pointer offset for ext4_inode_cache
      mm/slab: abstract slabobj_ext access via new slab_obj_ext() helper
      mm/slab: use stride to access slabobj_ext
      mm/memcontrol,alloc_tag: handle slabobj_ext access under KASAN poison
      mm/slab: save memory by allocating slabobj_ext array from leftover
      mm/slab: move [__]ksize and slab_ksize() to mm/slub.c
      mm/slab: place slabobj_ext metadata in unused space within s->size
      mm/slab: only allow SLAB_OBJ_EXT_IN_OBJ for unmergeable caches

Vlastimil Babka (24):
      slab: replace cache_from_obj() with inline checks
      mm/slab: add rcu_barrier() to kvfree_rcu_barrier_on_cache()
      slab: add SLAB_CONSISTENCY_CHECKS to SLAB_NEVER_MERGE
      mm/slab: move and refactor __kmem_cache_alias()
      mm/slab: make caches with sheaves mergeable
      slab: add sheaves to most caches
      slab: introduce percpu sheaves bootstrap
      slab: make percpu sheaves compatible with kmalloc_nolock()/kfree_nolock()
      slab: handle kmalloc sheaves bootstrap
      slab: add optimized sheaf refill from partial list
      slab: remove cpu (partial) slabs usage from allocation paths
      slab: remove SLUB_CPU_PARTIAL
      slab: remove the do_slab_free() fastpath
      slab: remove defer_deactivate_slab()
      slab: simplify kmalloc_nolock()
      slab: remove struct kmem_cache_cpu
      slab: remove unused PREEMPT_RT specific macros
      slab: refill sheaves from all nodes
      slab: update overview comments
      slab: remove frozen slab checks from __slab_free()
      mm/slub: remove DEACTIVATE_TO_* stat items
      mm/slub: cleanup and repurpose some stat items
      slub: avoid list_lock contention from __refill_objects_any()
      Merge branch 'slab/for-7.0/sheaves' into slab/for-next

 fs/ext4/super.c      |   19 +-
 include/linux/slab.h |   40 +-
 mm/Kconfig           |   11 -
 mm/internal.h        |    1 +
 mm/memcontrol.c      |   31 +-
 mm/page_alloc.c      |    5 +
 mm/slab.h            |  213 ++--
 mm/slab_common.c     |  153 ++-
 mm/slub.c            | 3215 ++++++++++++++++++++++----------------------------
 9 files changed, 1691 insertions(+), 1997 deletions(-)

Re: [GIT PULL] slab updates for 7.0

[Vlastimil Babka]

On 2/10/26 09:43, Vlastimil Babka wrote:
> Hi Linus,
> 
> please pull the latest slab updates from:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab.git tags/slab-for-7.0

Forgot to mention a small conflict with the last week's slab fix PR, as
noted by Mark: https://lore.kernel.org/all/aYShOPWbajIlXx_i@sirena.org.uk/

Re: [GIT PULL] slab updates for 7.0

[pr-tracker-bot]

The pull request you sent on Tue, 10 Feb 2026 09:43:31 +0100:

> git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab.git tags/slab-for-7.0

has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/148f95f75c513936d466bcc7e6bf73298da2212b

Thank you!

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