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* Merge tag 'mm-stable-2024-05-17-19-19' of ↵Linus Torvalds2024-05-191-188/+280
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm updates from Andrew Morton: "The usual shower of singleton fixes and minor series all over MM, documented (hopefully adequately) in the respective changelogs. Notable series include: - Lucas Stach has provided some page-mapping cleanup/consolidation/ maintainability work in the series "mm/treewide: Remove pXd_huge() API". - In the series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one test. - In their series "Memory allocation profiling" Kent Overstreet and Suren Baghdasaryan have contributed a means of determining (via /proc/allocinfo) whereabouts in the kernel memory is being allocated: number of calls and amount of memory. - Matthew Wilcox has provided the series "Various significant MM patches" which does a number of rather unrelated things, but in largely similar code sites. - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes Weiner has fixed the page allocator's handling of migratetype requests, with resulting improvements in compaction efficiency. - In the series "make the hugetlb migration strategy consistent" Baolin Wang has fixed a hugetlb migration issue, which should improve hugetlb allocation reliability. - Liu Shixin has hit an I/O meltdown caused by readahead in a memory-tight memcg. Addressed in the series "Fix I/O high when memory almost met memcg limit". - In the series "mm/filemap: optimize folio adding and splitting" Kairui Song has optimized pagecache insertion, yielding ~10% performance improvement in one test. - Baoquan He has cleaned up and consolidated the early zone initialization code in the series "mm/mm_init.c: refactor free_area_init_core()". - Baoquan has also redone some MM initializatio code in the series "mm/init: minor clean up and improvement". - MM helper cleanups from Christoph Hellwig in his series "remove follow_pfn". - More cleanups from Matthew Wilcox in the series "Various page->flags cleanups". - Vlastimil Babka has contributed maintainability improvements in the series "memcg_kmem hooks refactoring". - More folio conversions and cleanups in Matthew Wilcox's series: "Convert huge_zero_page to huge_zero_folio" "khugepaged folio conversions" "Remove page_idle and page_young wrappers" "Use folio APIs in procfs" "Clean up __folio_put()" "Some cleanups for memory-failure" "Remove page_mapping()" "More folio compat code removal" - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb functions to work on folis". - Code consolidation and cleanup work related to GUP's handling of hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2". - Rick Edgecombe has developed some fixes to stack guard gaps in the series "Cover a guard gap corner case". - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series "mm/ksm: fix ksm exec support for prctl". - Baolin Wang has implemented NUMA balancing for multi-size THPs. This is a simple first-cut implementation for now. The series is "support multi-size THP numa balancing". - Cleanups to vma handling helper functions from Matthew Wilcox in the series "Unify vma_address and vma_pgoff_address". - Some selftests maintenance work from Dev Jain in the series "selftests/mm: mremap_test: Optimizations and style fixes". - Improvements to the swapping of multi-size THPs from Ryan Roberts in the series "Swap-out mTHP without splitting". - Kefeng Wang has significantly optimized the handling of arm64's permission page faults in the series "arch/mm/fault: accelerate pagefault when badaccess" "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS" - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it GUP-fast". - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to use struct vm_fault". - selftests build fixes from John Hubbard in the series "Fix selftests/mm build without requiring "make headers"". - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes the initialization code so that migration between different memory types works as intended. - David Hildenbrand has improved follow_pte() and fixed an errant driver in the series "mm: follow_pte() improvements and acrn follow_pte() fixes". - David also did some cleanup work on large folio mapcounts in his series "mm: mapcount for large folios + page_mapcount() cleanups". - Folio conversions in KSM in Alex Shi's series "transfer page to folio in KSM". - Barry Song has added some sysfs stats for monitoring multi-size THP's in the series "mm: add per-order mTHP alloc and swpout counters". - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled and limit checking cleanups". - Matthew Wilcox has been looking at buffer_head code and found the documentation to be lacking. The series is "Improve buffer head documentation". - Multi-size THPs get more work, this time from Lance Yang. His series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes the freeing of these things. - Kemeng Shi has added more userspace-visible writeback instrumentation in the series "Improve visibility of writeback". - Kemeng Shi then sent some maintenance work on top in the series "Fix and cleanups to page-writeback". - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the series "Improve anon_vma scalability for anon VMAs". Intel's test bot reported an improbable 3x improvement in one test. - SeongJae Park adds some DAMON feature work in the series "mm/damon: add a DAMOS filter type for page granularity access recheck" "selftests/damon: add DAMOS quota goal test" - Also some maintenance work in the series "mm/damon/paddr: simplify page level access re-check for pageout" "mm/damon: misc fixes and improvements" - David Hildenbrand has disabled some known-to-fail selftests ni the series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL". - memcg metadata storage optimizations from Shakeel Butt in "memcg: reduce memory consumption by memcg stats". - DAX fixes and maintenance work from Vishal Verma in the series "dax/bus.c: Fixups for dax-bus locking"" * tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits) memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault selftests: cgroup: add tests to verify the zswap writeback path mm: memcg: make alloc_mem_cgroup_per_node_info() return bool mm/damon/core: fix return value from damos_wmark_metric_value mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED selftests: cgroup: remove redundant enabling of memory controller Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT Docs/mm/damon/design: use a list for supported filters Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file selftests/damon: classify tests for functionalities and regressions selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None' selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts selftests/damon/_damon_sysfs: check errors from nr_schemes file reads mm/damon/core: initialize ->esz_bp from damos_quota_init_priv() selftests/damon: add a test for DAMOS quota goal ...
| * mm, slab: move slab_memcg hooks to mm/memcontrol.cVlastimil Babka2024-04-261-101/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The hooks make multiple calls to functions in mm/memcontrol.c, including to th current_obj_cgroup() marked __always_inline. It might be faster to make a single call to the hook in mm/memcontrol.c instead. The hooks also don't use almost anything from mm/slub.c. obj_full_size() can move with the hooks and cache_vmstat_idx() to the internal mm/slab.h Link: https://lkml.kernel.org/r/20240326-slab-memcg-v3-2-d85d2563287a@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Brauner <brauner@kernel.org> Cc: Christoph Lameter <cl@linux.com> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Layton <jlayton@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Kees Cook <kees@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Pekka Enberg <penberg@kernel.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm, slab: move memcg charging to post-alloc hookVlastimil Babka2024-04-261-103/+77
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "memcg_kmem hooks refactoring", v3. This patch (of 2): The MEMCG_KMEM integration with slab currently relies on two hooks during allocation. memcg_slab_pre_alloc_hook() determines the objcg and charges it, and memcg_slab_post_alloc_hook() assigns the objcg pointer to the allocated object(s). As Linus pointed out, this is unnecessarily complex. Failing to charge due to memcg limits should be rare, so we can optimistically allocate the object(s) and do the charging together with assigning the objcg pointer in a single post_alloc hook. In the rare case the charging fails, we can free the object(s) back. This simplifies the code (no need to pass around the objcg pointer) and potentially allows to separate charging from allocation in cases where it's common that the allocation would be immediately freed, and the memcg handling overhead could be saved. [vbabka@suse.cz: fix call to memcg_alloc_abort_single()] Link: https://lkml.kernel.org/r/4af50be2-4109-45e5-8a36-2136252a635e@suse.cz [roman.gushchin@linux.dev: comment fixup] Link: https://lkml.kernel.org/r/Zg2LsNm6twOmG69l@P9FQF9L96D.corp.robot.car Link: https://lkml.kernel.org/r/20240326-slab-memcg-v3-0-d85d2563287a@suse.cz Link: https://lkml.kernel.org/r/20240326-slab-memcg-v3-1-d85d2563287a@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/all/CAHk-=whYOOdM7jWy5jdrAm8LxcgCMFyk2bt8fYYvZzM4U-zAQA@mail.gmail.com/ Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Christoph Lameter <cl@linux.com> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Layton <jlayton@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Kees Cook <kees@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Pekka Enberg <penberg@kernel.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Aishwarya TCV <aishwarya.tcv@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * slub: remove use of page->flagsMatthew Wilcox (Oracle)2024-04-261-8/+2
| | | | | | | | | | | | | | | | | | Use slub->__page_flags instead. We can also remove the assertion that it's not a tail page as struct slab never points to a tail page. Link: https://lkml.kernel.org/r/20240326171045.410737-9-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/slub: avoid recursive loop with kmemleakKees Cook2024-04-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The system will immediate fill up stack and crash when both CONFIG_DEBUG_KMEMLEAK and CONFIG_MEM_ALLOC_PROFILING are enabled. Avoid allocation tagging of kmemleak caches, otherwise recursive allocation tracking occurs. Link: https://lkml.kernel.org/r/20240425205516.work.220-kees@kernel.org Fixes: 279bb991b4d9 ("mm/slab: add allocation accounting into slab allocation and free paths") Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Catalin Marinas <catalin.marinas@arm.com> 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: Kent Overstreet <kent.overstreet@linux.dev> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * codetag: debug: introduce OBJEXTS_ALLOC_FAIL to mark failed slab_ext allocationsSuren Baghdasaryan2024-04-261-7/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If slabobj_ext vector allocation for a slab object fails and later on it succeeds for another object in the same slab, the slabobj_ext for the original object will be NULL and will be flagged in case when CONFIG_MEM_ALLOC_PROFILING_DEBUG is enabled. Mark failed slabobj_ext vector allocations using a new objext_flags flag stored in the lower bits of slab->obj_exts. When new allocation succeeds it marks all tag references in the same slabobj_ext vector as empty to avoid warnings implemented by CONFIG_MEM_ALLOC_PROFILING_DEBUG checks. Link: https://lkml.kernel.org/r/20240321163705.3067592-36-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Tested-by: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andreas Hindborg <a.hindborg@samsung.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Gary Guo <gary@garyguo.net> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * codetag: debug: skip objext checking when it's for objext itselfSuren Baghdasaryan2024-04-261-0/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | objext objects are created with __GFP_NO_OBJ_EXT flag and therefore have no corresponding objext themselves (otherwise we would get an infinite recursion). When freeing these objects their codetag will be empty and when CONFIG_MEM_ALLOC_PROFILING_DEBUG is enabled this will lead to false warnings. Introduce CODETAG_EMPTY special codetag value to mark allocations which intentionally lack codetag to avoid these warnings. Set objext codetags to CODETAG_EMPTY before freeing to indicate that the codetag is expected to be empty. Link: https://lkml.kernel.org/r/20240321163705.3067592-34-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Tested-by: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andreas Hindborg <a.hindborg@samsung.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Gary Guo <gary@garyguo.net> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/slab: enable slab allocation tagging for kmalloc and friendsSuren Baghdasaryan2024-04-261-25/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Redefine kmalloc, krealloc, kzalloc, kcalloc, etc. to record allocations and deallocations done by these functions. [surenb@google.com: undo _noprof additions in the documentation] Link: https://lkml.kernel.org/r/20240326231453.1206227-7-surenb@google.com [rdunlap@infradead.org: fix kcalloc() kernel-doc warnings] Link: https://lkml.kernel.org/r/20240327044649.9199-1-rdunlap@infradead.org Link: https://lkml.kernel.org/r/20240321163705.3067592-26-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Co-developed-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andreas Hindborg <a.hindborg@samsung.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Gary Guo <gary@garyguo.net> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/slab: add allocation accounting into slab allocation and free pathsSuren Baghdasaryan2024-04-261-1/+95
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Account slab allocations using codetag reference embedded into slabobj_ext. Link: https://lkml.kernel.org/r/20240321163705.3067592-24-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Co-developed-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andreas Hindborg <a.hindborg@samsung.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Gary Guo <gary@garyguo.net> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/slab: introduce SLAB_NO_OBJ_EXT to avoid obj_ext creationSuren Baghdasaryan2024-04-261-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Slab extension objects can't be allocated before slab infrastructure is initialized. Some caches, like kmem_cache and kmem_cache_node, are created before slab infrastructure is initialized. Objects from these caches can't have extension objects. Introduce SLAB_NO_OBJ_EXT slab flag to mark these caches and avoid creating extensions for objects allocated from these slabs. Link: https://lkml.kernel.org/r/20240321163705.3067592-9-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andreas Hindborg <a.hindborg@samsung.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Gary Guo <gary@garyguo.net> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: introduce __GFP_NO_OBJ_EXT flag to selectively prevent slabobj_ext creationSuren Baghdasaryan2024-04-261-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce __GFP_NO_OBJ_EXT flag in order to prevent recursive allocations when allocating slabobj_ext on a slab. Link: https://lkml.kernel.org/r/20240321163705.3067592-8-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andreas Hindborg <a.hindborg@samsung.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Gary Guo <gary@garyguo.net> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: introduce slabobj_ext to support slab object extensionsSuren Baghdasaryan2024-04-261-20/+81
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently slab pages can store only vectors of obj_cgroup pointers in page->memcg_data. Introduce slabobj_ext structure to allow more data to be stored for each slab object. Wrap obj_cgroup into slabobj_ext to support current functionality while allowing to extend slabobj_ext in the future. Link: https://lkml.kernel.org/r/20240321163705.3067592-7-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andreas Hindborg <a.hindborg@samsung.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Gary Guo <gary@garyguo.net> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/slub: mark slab_free_freelist_hook() __always_inlineKent Overstreet2024-04-261-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It seems we need to be more forceful with the compiler on this one. This is done for performance reasons only. Link: https://lkml.kernel.org/r/20240321163705.3067592-4-surenb@google.com Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andreas Hindborg <a.hindborg@samsung.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Gary Guo <gary@garyguo.net> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | Merge tag 'slab-for-6.10' of ↵Linus Torvalds2024-05-131-32/+86
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab updates from Vlastimil Babka: "This time it's mostly random cleanups and fixes, with two performance fixes that might have significant impact, but limited to systems experiencing particular bad corner case scenarios rather than general performance improvements. The memcg hook changes are going through the mm tree due to dependencies. - Prevent stalls when reading /proc/slabinfo (Jianfeng Wang) This fixes the long-standing problem that can happen with workloads that have alloc/free patterns resulting in many partially used slabs (in e.g. dentry cache). Reading /proc/slabinfo will traverse the long partial slab list under spinlock with disabled irqs and thus can stall other processes or even trigger the lockup detection. The traversal is only done to count free objects so that <active_objs> column can be reported along with <num_objs>. To avoid affecting fast paths with another shared counter (attempted in the past) or complex partial list traversal schemes that allow rescheduling, the chosen solution resorts to approximation - when the partial list is over 10000 slabs long, we will only traverse first 5000 slabs from head and tail each and use the average of those to estimate the whole list. Both head and tail are used as the slabs near head to tend to have more free objects than the slabs towards the tail. It is expected the approximation should not break existing /proc/slabinfo consumers. The <num_objs> field is still accurate and reflects the overall kmem_cache footprint. The <active_objs> was already imprecise due to cpu and percpu-partial slabs, so can't be relied upon to determine exact cache usage. The difference between <active_objs> and <num_objs> is mainly useful to determine the slab fragmentation, and that will be possible even with the approximation in place. - Prevent allocating many slabs when a NUMA node is full (Chen Jun) Currently, on NUMA systems with a node under significantly bigger pressure than other nodes, the fallback strategy may result in each kmalloc_node() that can't be safisfied from the preferred node, to allocate a new slab on a fallback node, and not reuse the slabs already on that node's partial list. This is now fixed and partial lists of fallback nodes are checked even for kmalloc_node() allocations. It's still preferred to allocate a new slab on the requested node before a fallback, but only with a GFP_NOWAIT attempt, which will fail quickly when the node is under a significant memory pressure. - More SLAB removal related cleanups (Xiu Jianfeng, Hyunmin Lee) - Fix slub_kunit self-test with hardened freelists (Guenter Roeck) - Mark racy accesses for KCSAN (linke li) - Misc cleanups (Xiongwei Song, Haifeng Xu, Sangyun Kim)" * tag 'slab-for-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: mm/slub: remove the check for NULL kmalloc_caches mm/slub: create kmalloc 96 and 192 caches regardless cache size order mm/slub: mark racy access on slab->freelist slub: use count_partial_free_approx() in slab_out_of_memory() slub: introduce count_partial_free_approx() slub: Set __GFP_COMP in kmem_cache by default mm/slub: remove duplicate initialization for early_kmem_cache_node_alloc() mm/slub: correct comment in do_slab_free() mm/slub, kunit: Use inverted data to corrupt kmem cache mm/slub: simplify get_partial_node() mm/slub: add slub_get_cpu_partial() helper mm/slub: remove the check of !kmem_cache_has_cpu_partial() mm/slub: Reduce memory consumption in extreme scenarios mm/slub: mark racy accesses on slab->slabs mm/slub: remove dummy slabinfo functions
| * | mm/slub: mark racy access on slab->freelistlinke li2024-05-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In deactivate_slab(), slab->freelist can be changed concurrently. Mark data race on slab->freelist as benign using READ_ONCE. This patch is aimed at reducing the number of benign races reported by KCSAN in order to focus future debugging effort on harmful races. Signed-off-by: linke li <lilinke99@qq.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | slub: use count_partial_free_approx() in slab_out_of_memory()Jianfeng Wang2024-04-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | slab_out_of_memory() uses count_partial() to get the exact count of free objects for each node. As it may get called in the slab allocation path, count_partial_free_approx() can be used to avoid the risk and overhead of traversing a long partial slab list. At the same time, show_slab_objects() still uses count_partial(). Thus, slub users can still have the option to access the exact count of objects via sysfs if the overhead is acceptable to them. Signed-off-by: Jianfeng Wang <jianfeng.w.wang@oracle.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | slub: introduce count_partial_free_approx()Jianfeng Wang2024-04-231-1/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When reading "/proc/slabinfo", the kernel needs to report the number of free objects for each kmem_cache. The current implementation uses count_partial() to get it by scanning each kmem_cache_node's partial slab list and summing free objects from every partial slab. This process must hold per-kmem_cache_node spinlock and disable IRQ, and may take a long time. Consequently, it can block slab allocations on other CPUs and cause timeouts for network devices, when the partial list is long. In production, even NMI watchdog can be triggered due to this matter: e.g., for "buffer_head", the number of partial slabs was observed to be ~1M in one kmem_cache_node. This problem was also confirmed by others [1-3]. Iterating a partial list to get the exact count of objects can cause soft lockups for a long list with or without the lock (e.g., if preemption is disabled), and may not be very useful: the object count can change after the lock is released. The approach of maintaining free-object counters requires atomic operations on the fast path [3]. So, the fix is to introduce count_partial_free_approx(). This function can be used for getting the free object count in a kmem_cache_node's partial list. It limits the number of slabs to scan and avoids scanning the whole list by giving an approximation for a long list. Suppose the limit is N. If the list's length is not greater than N, output the exact count by traversing the list; if its length is greater than N, output an approximated count by traversing a subset of the list. The proposed method is to scan N/2 slabs from the list's head and N/2 slabs from the tail. For a partial list with ~280K slabs, benchmarks show that it performs better than just counting from the list's head, after slabs get sorted by kmem_cache_shrink(). Default the limit to 10000, as it produces an approximation within 1% of the exact count for both scenarios. Then, use count_partial_free_approx() in get_slabinfo(). Benchmarks: Diff = (exact - approximated) / exact * Normal case (w/o kmem_cache_shrink()): | MAX_TO_SCAN | Diff (count from head)| Diff (count head+tail)| | 1000 | 0.43 % | 1.09 % | | 5000 | 0.06 % | 0.37 % | | 10000 | 0.02 % | 0.16 % | | 20000 | 0.009 % | -0.003 % | * Skewed case (w/ kmem_cache_shrink()): | MAX_TO_SCAN | Diff (count from head)| Diff (count head+tail)| | 1000 | 12.46 % | 6.75 % | | 5000 | 5.38 % | 1.27 % | | 10000 | 4.99 % | 0.22 % | | 20000 | 4.86 % | -0.06 % | [1] https://lore.kernel.org/linux-mm/alpine.DEB.2.21.2003031602460.1537@www.lameter.com/T/ [2] https://lore.kernel.org/lkml/alpine.DEB.2.22.394.2008071258020.55871@www.lameter.com/T/ [3] https://lore.kernel.org/lkml/1e01092b-140d-2bab-aeba-321a74a194ee@linux.com/T/ Signed-off-by: Jianfeng Wang <jianfeng.w.wang@oracle.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | slub: Set __GFP_COMP in kmem_cache by defaultHaifeng Xu2024-04-151-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now the __GFP_COMP is set only if the higher-order is not 0. However, __GFP_COMP flag can be set unconditionally because compound page can not be created in the order-0 case. And this can also simplify the code a bit (no need to check the order is 0 or not). Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | mm/slub: remove duplicate initialization for early_kmem_cache_node_alloc()Sangyun Kim2024-04-091-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The struct track for every object in a new slab is already set up by new_slab(), so remove the duplicate initialization in early_kmem_cache_node_alloc(). Co-developed-by: Hyunmin Lee <hyunminlr@gmail.com> Signed-off-by: Hyunmin Lee <hyunminlr@gmail.com> Co-developed-by: Jeungwoo Yoo <casionwoo@gmail.com> Signed-off-by: Jeungwoo Yoo <casionwoo@gmail.com> Signed-off-by: Sangyun Kim <sangyun.kim@snu.ac.kr> Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | mm/slub: correct comment in do_slab_free()Xiu Jianfeng2024-04-041-1/+1
| | | | | | | | | | | | | | | | | | | | | slab_alloc_node() should be __slab_alloc_node(). Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | mm/slub: simplify get_partial_node()Xiongwei Song2024-04-041-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The break conditions for filling cpu partial can be more readable and simple. If slub_get_cpu_partial() returns 0, we can confirm that we don't need to fill cpu partial, then we should break from the loop. On the other hand, we also should break from the loop if we have added enough cpu partial slabs. Meanwhile, the logic above gets rid of the #ifdef and also fixes a weird corner case that if we set cpu_partial_slabs to 0 from sysfs, we still allocate at least one here. Signed-off-by: Xiongwei Song <xiongwei.song@windriver.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | mm/slub: add slub_get_cpu_partial() helperXiongwei Song2024-04-041-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | Add slub_get_cpu_partial() and dummy function to help improve get_partial_node(). It can help remove #ifdef of CONFIG_SLUB_CPU_PARTIAL and improve filling cpu partial logic. Signed-off-by: Xiongwei Song <xiongwei.song@windriver.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | mm/slub: remove the check of !kmem_cache_has_cpu_partial()Xiongwei Song2024-04-041-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The check of !kmem_cache_has_cpu_partial(s) with CONFIG_SLUB_CPU_PARTIAL enabled here is always false. We have already checked kmem_cache_debug() earlier and if it was true, then we either continued or broke from the loop so we can't reach this code in that case and don't need to check kmem_cache_debug() as part of kmem_cache_has_cpu_partial() again. Here we can remove it. Signed-off-by: Xiongwei Song <xiongwei.song@windriver.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | mm/slub: Reduce memory consumption in extreme scenariosChen Jun2024-04-021-2/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When kmalloc_node() is called without __GFP_THISNODE and the target node lacks sufficient memory, SLUB allocates a folio from a different node other than the requested node, instead of taking a partial slab from it. However, since the allocated folio does not belong to the requested node, on the following allocation it is deactivated and added to the partial slab list of the node it belongs to. This behavior can result in excessive memory usage when the requested node has insufficient memory, as SLUB will repeatedly allocate folios from other nodes without reusing the previously allocated ones. To prevent memory wastage, when a preferred node is indicated (not NUMA_NO_NODE) but without a prior __GFP_THISNODE constraint: 1) try to get a partial slab from target node only by having __GFP_THISNODE in pc.flags for get_partial() 2) if 1) failed, try to allocate a new slab from target node with GFP_NOWAIT | __GFP_THISNODE opportunistically. 3) if 2) failed, retry with original gfpflags which will allow get_partial() try partial lists of other nodes before potentially allocating new page from other nodes Without a preferred node, or with __GFP_THISNODE constraint, the behavior remains unchanged. On qemu with 4 numa nodes and each numa has 1G memory. Write a test ko to call kmalloc_node(196, GFP_KERNEL, 3) for (4 * 1024 + 4) * 1024 times. cat /proc/slabinfo shows: kmalloc-256 4200530 13519712 256 32 2 : tunables.. after this patch, cat /proc/slabinfo shows: kmalloc-256 4200558 4200768 256 32 2 : tunables.. Signed-off-by: Chen Jun <chenjun102@huawei.com> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | mm/slub: mark racy accesses on slab->slabslinke li2024-03-251-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The reads of slab->slabs are racy because it may be changed by put_cpu_partial concurrently. In slabs_cpu_partial_show() and show_slab_objects(), slab->slabs is only used for showing information. Data-racy reads from shared variables that are used only for diagnostic purposes should typically use data_race(), since it is normally not a problem if the values are off by a little. This patch is aimed at reducing the number of benign races reported by KCSAN in order to focus future debugging effort on harmful races. Signed-off-by: linke li <lilinke99@qq.com> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | mm/slub: remove dummy slabinfo functionsXiu Jianfeng2024-03-251-10/+0
| |/ | | | | | | | | | | | | | | | | | | The SLAB implementation has been removed since 6.8, so there is no other version of slabinfo_show_stats() and slabinfo_write(), then we can remove these two dummy functions. Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* / mm/slub: avoid zeroing outside-object freepointer for single freeNicolas Bouchinet2024-05-011-23/+29
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 284f17ac13fe ("mm/slub: handle bulk and single object freeing separately") splits single and bulk object freeing in two functions slab_free() and slab_free_bulk() which leads slab_free() to call slab_free_hook() directly instead of slab_free_freelist_hook(). If `init_on_free` is set, slab_free_hook() zeroes the object. Afterward, if `slub_debug=F` and `CONFIG_SLAB_FREELIST_HARDENED` are set, the do_slab_free() slowpath executes freelist consistency checks and try to decode a zeroed freepointer which leads to a "Freepointer corrupt" detection in check_object(). During bulk free, slab_free_freelist_hook() isn't affected as it always sets it objects freepointer using set_freepointer() to maintain its reconstructed freelist after `init_on_free`. For single free, object's freepointer thus needs to be avoided when stored outside the object if `init_on_free` is set. The freepointer left as is, check_object() may later detect an invalid pointer value due to objects overflow. To reproduce, set `slub_debug=FU init_on_free=1 log_level=7` on the command line of a kernel build with `CONFIG_SLAB_FREELIST_HARDENED=y`. dmesg sample log: [ 10.708715] ============================================================================= [ 10.710323] BUG kmalloc-rnd-05-32 (Tainted: G B T ): Freepointer corrupt [ 10.712695] ----------------------------------------------------------------------------- [ 10.712695] [ 10.712695] Slab 0xffffd8bdc400d580 objects=32 used=4 fp=0xffff9d9a80356f80 flags=0x200000000000a00(workingset|slab|node=0|zone=2) [ 10.716698] Object 0xffff9d9a80356600 @offset=1536 fp=0x7ee4f480ce0ecd7c [ 10.716698] [ 10.716698] Bytes b4 ffff9d9a803565f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 10.720703] Object ffff9d9a80356600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 10.720703] Object ffff9d9a80356610: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 10.724696] Padding ffff9d9a8035666c: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 10.724696] Padding ffff9d9a8035667c: 00 00 00 00 .... [ 10.724696] FIX kmalloc-rnd-05-32: Object at 0xffff9d9a80356600 not freed Fixes: 284f17ac13fe ("mm/slub: handle bulk and single object freeing separately") Cc: <stable@vger.kernel.org> Co-developed-by: Chengming Zhou <chengming.zhou@linux.dev> Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev> Signed-off-by: Nicolas Bouchinet <nicolas.bouchinet@ssi.gouv.fr> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* Merge branch 'slab/for-6.9/slab-flag-cleanups' into slab/for-linusVlastimil Babka2024-03-121-3/+3
|\ | | | | | | | | | | Merge a series from myself that replaces hardcoded SLAB_ cache flag values with an enum, and explicitly deprecates the SLAB_MEM_SPREAD flag that is a no-op sine SLAB removal.
| * mm, slab: use an enum to define SLAB_ cache creation flagsVlastimil Babka2024-02-261-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The values of SLAB_ cache creation flags are defined by hand, which is tedious and error-prone. Use an enum to assign the bit number and a __SLAB_FLAG_BIT() macro to #define the final flags. This renumbers the flag values, which is OK as they are only used internally. Also define a __SLAB_FLAG_UNUSED macro to assign value to flags disabled by their respective config options in a unified and sparse-friendly way. Reviewed-and-tested-by: Xiongwei Song <xiongwei.song@windriver.com> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | Merge branch 'slab/for-6.9/optimize-get-freelist' into slab/for-linusVlastimil Babka2024-03-121-18/+14
|\ \ | | | | | | | | | | | | Merge a series from Chengming Zhou that optimizes cpu freelist loading when grabbing a cpu partial slab, and removes some unnecessary code.
| * | mm/slub: remove unused parameter in next_freelist_entry()Chengming Zhou2024-01-231-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The parameter "struct slab *slab" is unused in next_freelist_entry(), so just remove it. Acked-by: Christoph Lameter (Ampere) <cl@linux.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | mm/slub: remove full list manipulation for non-debug slabChengming Zhou2024-01-231-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since debug slab is processed by free_to_partial_list(), and only debug slab which has SLAB_STORE_USER flag would care about the full list, we can remove these unrelated full list manipulations from __slab_free(). Acked-by: Christoph Lameter (Ampere) <cl@linux.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | mm/slub: directly load freelist from cpu partial slab in the likely caseChengming Zhou2024-01-231-10/+11
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The likely case is that we get a usable slab from the cpu partial list, we can directly load freelist from it and return back, instead of going the other way that need more work, like reenable interrupt and recheck. But we need to remove the "VM_BUG_ON(!new.frozen)" in get_freelist() for reusing it, since cpu partial slab is not frozen. It seems acceptable since it's only for debug purpose. And get_freelist() also assumes it can return NULL if the freelist is empty, which is not possible for the cpu partial slab case, so we add "VM_BUG_ON(!freelist)" after get_freelist() to make it explicit. There is some small performance improvement too, which shows by: perf bench sched messaging -g 5 -t -l 100000 mm-stable slub-optimize Total time 7.473 7.209 Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | mm, slab: remove memcg_from_slab_obj()Vlastimil Babka2024-03-041-5/+0
| | | | | | | | | | | | | | | | | | | | This empty wrapped exists only for !CONFIG_MEMCG_KMEM and seems it was never used. Probably a leftover from development of a series. Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | mm, slab: remove the corner case of inc_slabs_node()Chengming Zhou2024-03-011-11/+2
| | | | | | | | | | | | | | | | | | | | We already have the inc_slabs_node() after kmem_cache_node->node[node] initialized in early_kmem_cache_node_alloc(), this special case of inc_slabs_node() can be removed. Then we don't need to consider the existence of kmem_cache_node in inc_slabs_node() anymore. Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/slab: Fix a kmemleak in kmem_cache_destroy()Xiaolei Wang2024-03-011-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For earlier kmem cache creation, slab_sysfs_init() has not been called. Consequently, kmem_cache_destroy() cannot utilize kobj_type::release to release the kmem_cache structure. Therefore, tweak kmem_cache_release() to use slab_kmem_cache_release() for releasing kmem_cache when slab_state isn't FULL. This will fixes the memory leaks like following: unreferenced object 0xffff0000c2d87080 (size 128): comm "swapper/0", pid 1, jiffies 4294893428 hex dump (first 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 6b 6b 6b 6b .....N......kkkk ff ff ff ff ff ff ff ff b8 ab 48 89 00 80 ff ff.....H..... backtrace (crc 8819d0f6): [<ffff80008317a298>] kmemleak_alloc+0xb0/0xc4 [<ffff8000807e553c>] kmem_cache_alloc_node+0x288/0x3a8 [<ffff8000807e95f0>] __kmem_cache_create+0x1e4/0x64c [<ffff8000807216bc>] kmem_cache_create_usercopy+0x1c4/0x2cc [<ffff8000807217e0>] kmem_cache_create+0x1c/0x28 [<ffff8000819f6278>] arm_v7s_alloc_pgtable+0x1c0/0x6d4 [<ffff8000819f53a0>] alloc_io_pgtable_ops+0xe8/0x2d0 [<ffff800084b2d2c4>] arm_v7s_do_selftests+0xe0/0x73c [<ffff800080016b68>] do_one_initcall+0x11c/0x7ac [<ffff800084a71ddc>] kernel_init_freeable+0x53c/0xbb8 [<ffff8000831728d8>] kernel_init+0x24/0x144 [<ffff800080018e98>] ret_from_fork+0x10/0x20 Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | mm, slab: fix the comment of cpu partial listChengming Zhou2024-02-211-1/+1
| | | | | | | | | | | | | | | | | | The partial slabs on cpu partial list are not frozen after the commit 8cd3fa428b56 ("slub: Delay freezing of partial slabs") merged. So fix the comment. Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | mm, slab: remove unused object_size parameter in kmem_cache_flags()Chengming Zhou2024-02-211-6/+3
| | | | | | | | | | | | | | | | We don't use the object_size parameter in kmem_cache_flags(), so just remove it. Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/slub: remove parameter 'flags' in create_kmalloc_caches()Zheng Yejian2024-01-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After commit 16a1d968358a ("mm/slab: remove mm/slab.c and slab_def.h"), parameter 'flags' is only passed as 0 in create_kmalloc_caches(), and then it is only passed to new_kmalloc_cache(). So we can change parameter 'flags' to be a local variable with initial value 0 in new_kmalloc_cache() and remove parameter 'flags' in create_kmalloc_caches(). Also make new_kmalloc_cache() static due to it is only used in mm/slab_common.c. Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/slub: unify all sl[au]b parameters with "slab_$param"Xiongwei Song2024-01-221-18/+23
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the SLAB allocator has been removed, so we can clean up the sl[au]b_$params. With only one slab allocator left, it's better to use the generic "slab" term instead of "slub" which is an implementation detail, which is pointed out by Vlastimil Babka. For more information please see [1]. Hence, we are going to use "slab_$param" as the primary prefix. This patch is changing the following slab parameters - slub_max_order - slub_min_order - slub_min_objects - slub_debug to - slab_max_order - slab_min_order - slab_min_objects - slab_debug as the primary slab parameters for all references of them in docs and comments. But this patch won't change variables and functions inside slub as we will have wider slub/slab change. Meanwhile, "slub_$params" can also be passed by command line, which is to keep backward compatibility. Also mark all "slub_$params" as legacy. Remove the separate descriptions for slub_[no]merge, append legacy tip for them at the end of descriptions of slab_[no]merge. [1] https://lore.kernel.org/linux-mm/7512b350-4317-21a0-fab3-4101bc4d8f7a@suse.cz/ Signed-off-by: Xiongwei Song <xiongwei.song@windriver.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* Merge tag 'mm-stable-2024-01-08-15-31' of ↵Linus Torvalds2024-01-091-31/+38
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Many singleton patches against the MM code. The patch series which are included in this merge do the following: - Peng Zhang has done some mapletree maintainance work in the series 'maple_tree: add mt_free_one() and mt_attr() helpers' 'Some cleanups of maple tree' - In the series 'mm: use memmap_on_memory semantics for dax/kmem' Vishal Verma has altered the interworking between memory-hotplug and dax/kmem so that newly added 'device memory' can more easily have its memmap placed within that newly added memory. - Matthew Wilcox continues folio-related work (including a few fixes) in the patch series 'Add folio_zero_tail() and folio_fill_tail()' 'Make folio_start_writeback return void' 'Fix fault handler's handling of poisoned tail pages' 'Convert aops->error_remove_page to ->error_remove_folio' 'Finish two folio conversions' 'More swap folio conversions' - Kefeng Wang has also contributed folio-related work in the series 'mm: cleanup and use more folio in page fault' - Jim Cromie has improved the kmemleak reporting output in the series 'tweak kmemleak report format'. - In the series 'stackdepot: allow evicting stack traces' Andrey Konovalov to permits clients (in this case KASAN) to cause eviction of no longer needed stack traces. - Charan Teja Kalla has fixed some accounting issues in the page allocator's atomic reserve calculations in the series 'mm: page_alloc: fixes for high atomic reserve caluculations'. - Dmitry Rokosov has added to the samples/ dorectory some sample code for a userspace memcg event listener application. See the series 'samples: introduce cgroup events listeners'. - Some mapletree maintanance work from Liam Howlett in the series 'maple_tree: iterator state changes'. - Nhat Pham has improved zswap's approach to writeback in the series 'workload-specific and memory pressure-driven zswap writeback'. - DAMON/DAMOS feature and maintenance work from SeongJae Park in the series 'mm/damon: let users feed and tame/auto-tune DAMOS' 'selftests/damon: add Python-written DAMON functionality tests' 'mm/damon: misc updates for 6.8' - Yosry Ahmed has improved memcg's stats flushing in the series 'mm: memcg: subtree stats flushing and thresholds'. - In the series 'Multi-size THP for anonymous memory' Ryan Roberts has added a runtime opt-in feature to transparent hugepages which improves performance by allocating larger chunks of memory during anonymous page faults. - Matthew Wilcox has also contributed some cleanup and maintenance work against eh buffer_head code int he series 'More buffer_head cleanups'. - Suren Baghdasaryan has done work on Andrea Arcangeli's series 'userfaultfd move option'. UFFDIO_MOVE permits userspace heap compaction algorithms to move userspace's pages around rather than UFFDIO_COPY'a alloc/copy/free. - Stefan Roesch has developed a 'KSM Advisor', in the series 'mm/ksm: Add ksm advisor'. This is a governor which tunes KSM's scanning aggressiveness in response to userspace's current needs. - Chengming Zhou has optimized zswap's temporary working memory use in the series 'mm/zswap: dstmem reuse optimizations and cleanups'. - Matthew Wilcox has performed some maintenance work on the writeback code, both code and within filesystems. The series is 'Clean up the writeback paths'. - Andrey Konovalov has optimized KASAN's handling of alloc and free stack traces for secondary-level allocators, in the series 'kasan: save mempool stack traces'. - Andrey also performed some KASAN maintenance work in the series 'kasan: assorted clean-ups'. - David Hildenbrand has gone to town on the rmap code. Cleanups, more pte batching, folio conversions and more. See the series 'mm/rmap: interface overhaul'. - Kinsey Ho has contributed some maintenance work on the MGLRU code in the series 'mm/mglru: Kconfig cleanup'. - Matthew Wilcox has contributed lruvec page accounting code cleanups in the series 'Remove some lruvec page accounting functions'" * tag 'mm-stable-2024-01-08-15-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (361 commits) mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER mm, treewide: introduce NR_PAGE_ORDERS selftests/mm: add separate UFFDIO_MOVE test for PMD splitting selftests/mm: skip test if application doesn't has root privileges selftests/mm: conform test to TAP format output selftests: mm: hugepage-mmap: conform to TAP format output selftests/mm: gup_test: conform test to TAP format output mm/selftests: hugepage-mremap: conform test to TAP format output mm/vmstat: move pgdemote_* out of CONFIG_NUMA_BALANCING mm: zsmalloc: return -ENOSPC rather than -EINVAL in zs_malloc while size is too large mm/memcontrol: remove __mod_lruvec_page_state() mm/khugepaged: use a folio more in collapse_file() slub: use a folio in __kmalloc_large_node slub: use folio APIs in free_large_kmalloc() slub: use alloc_pages_node() in alloc_slab_page() mm: remove inc/dec lruvec page state functions mm: ratelimit stat flush from workingset shrinker kasan: stop leaking stack trace handles mm/mglru: remove CONFIG_TRANSPARENT_HUGEPAGE mm/mglru: add dummy pmd_dirty() ...
| * mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDERKirill A. Shutemov2024-01-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 23baf831a32c ("mm, treewide: redefine MAX_ORDER sanely") has changed the definition of MAX_ORDER to be inclusive. This has caused issues with code that was not yet upstream and depended on the previous definition. To draw attention to the altered meaning of the define, rename MAX_ORDER to MAX_PAGE_ORDER. Link: https://lkml.kernel.org/r/20231228144704.14033-2-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * slub: use alloc_pages_node() in alloc_slab_page()Matthew Wilcox (Oracle)2024-01-051-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | For no apparent reason, we were open-coding alloc_pages_node() in this function. Link: https://lkml.kernel.org/r/20231228085748.1083901-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: David Rientjes <rientjes@google.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * kasan: rename and document kasan_(un)poison_object_dataAndrey Konovalov2023-12-291-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename kasan_unpoison_object_data to kasan_unpoison_new_object and add a documentation comment. Do the same for kasan_poison_object_data. The new names and the comments should suggest the users that these hooks are intended for internal use by the slab allocator. The following patch will remove non-slab-internal uses of these hooks. No functional changes. [andreyknvl@google.com: update references to renamed functions in comments] Link: https://lkml.kernel.org/r/20231221180637.105098-1-andrey.konovalov@linux.dev Link: https://lkml.kernel.org/r/eab156ebbd635f9635ef67d1a4271f716994e628.1703024586.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * slub, kasan: improve interaction of KASAN and slub_debug poisoningAndrey Konovalov2023-12-111-15/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When both KASAN and slub_debug are enabled, when a free object is being prepared in setup_object, slub_debug poisons the object data before KASAN initializes its per-object metadata. Right now, in setup_object, KASAN only initializes the alloc metadata, which is always stored outside of the object. slub_debug is aware of this and it skips poisoning and checking that memory area. However, with the following patch in this series, KASAN also starts initializing its free medata in setup_object. As this metadata might be stored within the object, this initialization might overwrite the slub_debug poisoning. This leads to slub_debug reports. Thus, skip checking slub_debug poisoning of the object data area that overlaps with the in-object KASAN free metadata. Also make slub_debug poisoning of tail kmalloc redzones more precise when KASAN is enabled: slub_debug can still poison and check the tail kmalloc allocation area that comes after the KASAN free metadata. Link: https://lkml.kernel.org/r/20231122231202.121277-1-andrey.konovalov@linux.dev Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Marco Elver <elver@google.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | Merge branch 'slab/for-6.8/slub-hook-cleanups' into slab/for-nextVlastimil Babka2024-01-041-64/+679
|\ \ | | | | | | | | | | | | Merge the SLAB allocator removal and a number of subsequent SLUB cleanups and optimizations.
| * | mm/slub: free KFENCE objects in slab_free_hook()Vlastimil Babka2023-12-281-12/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When freeing an object that was allocated from KFENCE, we do that in the slowpath __slab_free(), relying on the fact that KFENCE "slab" cannot be the cpu slab, so the fastpath has to fallback to the slowpath. This optimization doesn't help much though, because is_kfence_address() is checked earlier anyway during the free hook processing or detached freelist building. Thus we can simplify the code by making the slab_free_hook() free the KFENCE object immediately, similarly to KASAN quarantine. In slab_free_hook() we can place kfence_free() above init processing, as callers have been making sure to set init to false for KFENCE objects. This simplifies slab_free(). This places it also above kasan_slab_free() which is ok as that skips KFENCE objects anyway. While at it also determine the init value in slab_free_freelist_hook() outside of the loop. This change will also make introducing per cpu array caches easier. Tested-by: Marco Elver <elver@google.com> Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | mm/slub: handle bulk and single object freeing separatelyVlastimil Babka2023-12-071-24/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we have a single function slab_free() handling both single object freeing and bulk freeing with necessary hooks, the latter case requiring slab_free_freelist_hook(). It should be however better to distinguish the two use cases for the following reasons: - code simpler to follow for the single object case - better code generation - although inlining should eliminate the slab_free_freelist_hook() for single object freeing in case no debugging options are enabled, it seems it's not perfect. When e.g. KASAN is enabled, we're imposing additional unnecessary overhead for single object freeing. - preparation to add percpu array caches in near future Therefore, simplify slab_free() for the single object case by dropping unnecessary parameters and calling only slab_free_hook() instead of slab_free_freelist_hook(). Rename the bulk variant to slab_free_bulk() and adjust callers accordingly. While at it, flip (and document) slab_free_hook() return value so that it returns true when the freeing can proceed, which matches the logic of slab_free_freelist_hook() and is not confusingly the opposite. Additionally we can simplify a bit by changing the tail parameter of do_slab_free() when freeing a single object - instead of NULL we can set it equal to head. bloat-o-meter shows small code reduction with a .config that has KASAN etc disabled: add/remove: 0/0 grow/shrink: 0/4 up/down: 0/-118 (-118) Function old new delta kmem_cache_alloc_bulk 1203 1196 -7 kmem_cache_free 861 835 -26 __kmem_cache_free 741 704 -37 kmem_cache_free_bulk 911 863 -48 Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | mm/slub: introduce __kmem_cache_free_bulk() without free hooksVlastimil Babka2023-12-071-9/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, when __kmem_cache_alloc_bulk() fails, it frees back the objects that were allocated before the failure, using kmem_cache_free_bulk(). Because kmem_cache_free_bulk() calls the free hooks (KASAN etc.) and those expect objects that were processed by the post alloc hooks, slab_post_alloc_hook() is called before kmem_cache_free_bulk(). This is wasteful, although not a big concern in practice for the rare error path. But in order to efficiently handle percpu array batch refill and free in the near future, we will also need a variant of kmem_cache_free_bulk() that avoids the free hooks. So introduce it now and use it for the failure path. In case of failure we however still need to perform memcg uncharge so handle that in a new memcg_slab_alloc_error_hook(). Thanks to Chengming Zhou for noticing the missing uncharge. As a consequence, __kmem_cache_alloc_bulk() no longer needs the objcg parameter, remove it. Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | mm/slub: fix bulk alloc and free statsVlastimil Babka2023-12-071-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The SLUB sysfs stats enabled CONFIG_SLUB_STATS have two deficiencies identified wrt bulk alloc/free operations: - Bulk allocations from cpu freelist are not counted. Add the ALLOC_FASTPATH counter there. - Bulk fastpath freeing will count a list of multiple objects with a single FREE_FASTPATH inc. Add a stat_add() variant to count them all. Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>