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2022-04-15mm, kfence: support kmem_dump_obj() for KFENCE objectsMarco Elver1-1/+1
Calling kmem_obj_info() via kmem_dump_obj() on KFENCE objects has been producing garbage data due to the object not actually being maintained by SLAB or SLUB. Fix this by implementing __kfence_obj_info() that copies relevant information to struct kmem_obj_info when the object was allocated by KFENCE; this is called by a common kmem_obj_info(), which also calls the slab/slub/slob specific variant now called __kmem_obj_info(). For completeness, kmem_dump_obj() now displays if the object was allocated by KFENCE. Link: https://lore.kernel.org/all/20220323090520.GG16885@xsang-OptiPlex-9020/ Link: https://lkml.kernel.org/r/20220406131558.3558585-1-elver@google.com Fixes: b89fb5ef0ce6 ("mm, kfence: insert KFENCE hooks for SLUB") Fixes: d3fb45f370d9 ("mm, kfence: insert KFENCE hooks for SLAB") Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reported-by: kernel test robot <oliver.sang@intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> [slab] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22mm: introduce kmem_cache_alloc_lruMuchun Song1-4/+21
We currently allocate scope for every memcg to be able to tracked on every superblock instantiated in the system, regardless of whether that superblock is even accessible to that memcg. These huge memcg counts come from container hosts where memcgs are confined to just a small subset of the total number of superblocks that instantiated at any given point in time. For these systems with huge container counts, list_lru does not need the capability of tracking every memcg on every superblock. What it comes down to is that adding the memcg to the list_lru at the first insert. So introduce kmem_cache_alloc_lru to allocate objects and its list_lru. In the later patch, we will convert all inode and dentry allocation from kmem_cache_alloc to kmem_cache_alloc_lru. Link: https://lkml.kernel.org/r/20220228122126.37293-3-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Cc: Alex Shi <alexs@kernel.org> Cc: Anna Schumaker <Anna.Schumaker@Netapp.com> Cc: Chao Yu <chao@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Fam Zheng <fam.zheng@bytedance.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kari Argillander <kari.argillander@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-18Merge tag 'slab-for-5.17-part2' of ↵Linus Torvalds1-6/+0
git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull more slab updates from Vlastimil Babka: "Finish the conversion to struct slab by removing slab-specific fields from struct page. The first slab update (see merge commit ca1a46d6f506) did most of the conversion, but there was also series in iommu tree removing the iommu's usage of struct page 'freelist' field, blocking the final struct page cleanup. Now that the iommu changes have been merged, we can finish the job" * tag 'slab-for-5.17-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: mm: Remove slab from struct page
2022-01-15Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-5/+0
Merge misc updates from Andrew Morton: "146 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, vfs, and mm (slab-generic, slab, kmemleak, dax, kasan, debug, pagecache, gup, shmem, frontswap, memremap, memcg, selftests, pagemap, dma, vmalloc, memory-failure, hugetlb, userfaultfd, vmscan, mempolicy, oom-kill, hugetlbfs, migration, thp, ksm, page-poison, percpu, rmap, zswap, zram, cleanups, hmm, and damon)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (146 commits) mm/damon: hide kernel pointer from tracepoint event mm/damon/vaddr: hide kernel pointer from damon_va_three_regions() failure log mm/damon/vaddr: use pr_debug() for damon_va_three_regions() failure logging mm/damon/dbgfs: remove an unnecessary variable mm/damon: move the implementation of damon_insert_region to damon.h mm/damon: add access checking for hugetlb pages Docs/admin-guide/mm/damon/usage: update for schemes statistics mm/damon/dbgfs: support all DAMOS stats Docs/admin-guide/mm/damon/reclaim: document statistics parameters mm/damon/reclaim: provide reclamation statistics mm/damon/schemes: account how many times quota limit has exceeded mm/damon/schemes: account scheme actions that successfully applied mm/damon: remove a mistakenly added comment for a future feature Docs/admin-guide/mm/damon/usage: update for kdamond_pid and (mk|rm)_contexts Docs/admin-guide/mm/damon/usage: mention tracepoint at the beginning Docs/admin-guide/mm/damon/usage: remove redundant information Docs/admin-guide/mm/damon/usage: update for scheme quotas and watermarks mm/damon: convert macro functions to static inline functions mm/damon: modify damon_rand() macro to static inline function mm/damon: move damon_rand() definition into damon.h ...
2022-01-15mm: slab: make slab iterator functions staticMuchun Song1-5/+0
There is no external users of slab_start/next/stop(), so make them static. And the memory.kmem.slabinfo is deprecated, which outputs nothing now, so move memcg_slab_show() into mm/memcontrol.c and rename it to mem_cgroup_slab_show to be consistent with other function names. Link: https://lkml.kernel.org/r/20211109133359.32881-1-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-06mm: Remove slab from struct pageMatthew Wilcox (Oracle)1-6/+0
All members of struct slab can now be removed from struct page. This shrinks the definition of struct page by 30 LOC, making it easier to understand. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2022-01-06mm/slob: Remove unnecessary page_mapcount_reset() function callHyeonggon Yoo1-2/+2
After commit 401fb12c68c2 ("mm/sl*b: Differentiate struct slab fields by sl*b implementations"), we can reorder fields of struct slab depending on slab allocator. For now, page_mapcount_reset() is called because page->_mapcount and slab->units have same offset. But this is not necessary for struct slab. Use unused field for units instead. Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Link: https://lore.kernel.org/r/20211212065241.GA886691@odroid
2022-01-06mm/slub: Define struct slab fields for CONFIG_SLUB_CPU_PARTIAL only when enabledVlastimil Babka1-0/+2
The fields 'next' and 'slabs' are only used when CONFIG_SLUB_CPU_PARTIAL is enabled. We can put their definition to #ifdef to prevent accidental use when disabled. Currenlty show_slab_objects() and slabs_cpu_partial_show() contain code accessing the slabs field that's effectively dead with CONFIG_SLUB_CPU_PARTIAL=n through the wrappers slub_percpu_partial() and slub_percpu_partial_read_once(), but to prevent a compile error, we need to hide all this code behind #ifdef. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Roman Gushchin <guro@fb.com> Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
2022-01-06mm/slub: Simplify struct slab slabs field definitionVlastimil Babka1-4/+0
Before commit b47291ef02b0 ("mm, slub: change percpu partial accounting from objects to pages") we had to fit two integer fields into a native word size, so we used short int on 32-bit and int on 64-bit via #ifdef. After that commit there is only one integer field, so we can simply define it as int everywhere. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Roman Gushchin <guro@fb.com>
2022-01-06mm/sl*b: Differentiate struct slab fields by sl*b implementationsVlastimil Babka1-10/+38
With a struct slab definition separate from struct page, we can go further and define only fields that the chosen sl*b implementation uses. This means everything between __page_flags and __page_refcount placeholders now depends on the chosen CONFIG_SL*B. Some fields exist in all implementations (slab_list) but can be part of a union in some, so it's simpler to repeat them than complicate the definition with ifdefs even more. The patch doesn't change physical offsets of the fields, although it could be done later - for example it's now clear that tighter packing in SLOB could be possible. This should also prevent accidental use of fields that don't exist in given implementation. Before this patch virt_to_cache() and cache_from_obj() were visible for SLOB (albeit not used), although they rely on the slab_cache field that isn't set by SLOB. With this patch it's now a compile error, so these functions are now hidden behind an #ifndef CONFIG_SLOB. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Roman Gushchin <guro@fb.com> Tested-by: Marco Elver <elver@google.com> # kfence Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: <kasan-dev@googlegroups.com>
2022-01-06mm/memcg: Convert slab objcgs from struct page to struct slabVlastimil Babka1-23/+50
page->memcg_data is used with MEMCG_DATA_OBJCGS flag only for slab pages so convert all the related infrastructure to struct slab. Also use struct folio instead of struct page when resolving object pointers. This is not just mechanistic changing of types and names. Now in mem_cgroup_from_obj() we use folio_test_slab() to decide if we interpret the folio as a real slab instead of a large kmalloc, instead of relying on MEMCG_DATA_OBJCGS bit that used to be checked in page_objcgs_check(). Similarly in memcg_slab_free_hook() where we can encounter kmalloc_large() pages (here the folio slab flag check is implied by virt_to_slab()). As a result, page_objcgs_check() can be dropped instead of converted. To avoid include cycles, move the inline definition of slab_objcgs() from memcontrol.h to mm/slab.h. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Roman Gushchin <guro@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: <cgroups@vger.kernel.org>
2022-01-06mm: Convert struct page to struct slab in functions used by other subsystemsVlastimil Babka1-2/+2
KASAN, KFENCE and memcg interact with SLAB or SLUB internals through functions nearest_obj(), obj_to_index() and objs_per_slab() that use struct page as parameter. This patch converts it to struct slab including all callers, through a coccinelle semantic patch. // Options: --include-headers --no-includes --smpl-spacing include/linux/slab_def.h include/linux/slub_def.h mm/slab.h mm/kasan/*.c mm/kfence/kfence_test.c mm/memcontrol.c mm/slab.c mm/slub.c // Note: needs coccinelle 1.1.1 to avoid breaking whitespace @@ @@ -objs_per_slab_page( +objs_per_slab( ... ) { ... } @@ @@ -objs_per_slab_page( +objs_per_slab( ... ) @@ identifier fn =~ "obj_to_index|objs_per_slab"; @@ fn(..., - const struct page *page + const struct slab *slab ,...) { <... ( - page_address(page) + slab_address(slab) | - page + slab ) ...> } @@ identifier fn =~ "nearest_obj"; @@ fn(..., - struct page *page + const struct slab *slab ,...) { <... ( - page_address(page) + slab_address(slab) | - page + slab ) ...> } @@ identifier fn =~ "nearest_obj|obj_to_index|objs_per_slab"; expression E; @@ fn(..., ( - slab_page(E) + E | - virt_to_page(E) + virt_to_slab(E) | - virt_to_head_page(E) + virt_to_slab(E) | - page + page_slab(page) ) ,...) Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Reviewed-by: Roman Gushchin <guro@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Julia Lawall <julia.lawall@inria.fr> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: <kasan-dev@googlegroups.com> Cc: <cgroups@vger.kernel.org>
2022-01-06mm: Convert check_heap_object() to use struct slabMatthew Wilcox (Oracle)1-0/+11
Ensure that we're not seeing a tail page inside __check_heap_object() by converting to a slab instead of a page. Take the opportunity to mark the slab as const since we're not modifying it. Also move the declaration of __check_heap_object() to mm/slab.h so it's not available to the wider kernel. [ vbabka@suse.cz: in check_heap_object() only convert to struct slab for actual PageSlab pages; use folio as intermediate step instead of page ] Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Roman Gushchin <guro@fb.com>
2022-01-06mm: Use struct slab in kmem_obj_info()Matthew Wilcox (Oracle)1-2/+2
All three implementations of slab support kmem_obj_info() which reports details of an object allocated from the slab allocator. By using the slab type instead of the page type, we make it obvious that this can only be called for slabs. [ vbabka@suse.cz: also convert the related kmem_valid_obj() to folios ] Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Roman Gushchin <guro@fb.com>
2022-01-06mm: Convert virt_to_cache() to use struct slabMatthew Wilcox (Oracle)1-4/+4
This function is entirely self-contained, so can be converted from page to slab. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Roman Gushchin <guro@fb.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
2022-01-06mm: Convert [un]account_slab_page() to struct slabMatthew Wilcox (Oracle)1-9/+8
Convert the parameter of these functions to struct slab instead of struct page and drop _page from the names. For now their callers just convert page to slab. [ vbabka@suse.cz: replace existing functions instead of calling them ] Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Roman Gushchin <guro@fb.com>
2022-01-06mm: Split slab into its own typeMatthew Wilcox (Oracle)1-0/+167
Make struct slab independent of struct page. It still uses the underlying memory in struct page for storing slab-specific data, but slab and slub can now be weaned off using struct page directly. Some of the wrapper functions (slab_address() and slab_order()) still need to cast to struct folio, but this is a significant disentanglement. [ vbabka@suse.cz: Rebase on folios, use folio instead of page where possible. Do not duplicate flags field in struct slab, instead make the related accessors go through slab_folio(). For testing pfmemalloc use the folio_*_active flag accessors directly so the PageSlabPfmemalloc wrappers can be removed later. Make folio_slab() expect only folio_test_slab() == true folios and virt_to_slab() return NULL when folio_test_slab() == false. Move struct slab to mm/slab.h. Don't represent with struct slab pages that are not true slab pages, but just a compound page obtained directly rom page allocator (with large kmalloc() for SLUB and SLOB). ] Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Roman Gushchin <guro@fb.com>
2021-11-20mm: kmemleak: slob: respect SLAB_NOLEAKTRACE flagRustam Kovhaev1-1/+1
When kmemleak is enabled for SLOB, system does not boot and does not print anything to the console. At the very early stage in the boot process we hit infinite recursion from kmemleak_init() and eventually kernel crashes. kmemleak_init() specifies SLAB_NOLEAKTRACE for KMEM_CACHE(), but kmem_cache_create_usercopy() removes it because CACHE_CREATE_MASK is not valid for SLOB. Let's fix CACHE_CREATE_MASK and make kmemleak work with SLOB Link: https://lkml.kernel.org/r/20211115020850.3154366-1-rkovhaev@gmail.com Fixes: d8843922fba4 ("slab: Ignore internal flags in cache creation") Signed-off-by: Rustam Kovhaev <rkovhaev@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Glauber Costa <glommer@parallels.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-30mm/memcg: fix NULL pointer dereference in memcg_slab_free_hook()Wang Hai1-1/+1
When I use kfree_rcu() to free a large memory allocated by kmalloc_node(), the following dump occurs. BUG: kernel NULL pointer dereference, address: 0000000000000020 [...] Oops: 0000 [#1] SMP [...] Workqueue: events kfree_rcu_work RIP: 0010:__obj_to_index include/linux/slub_def.h:182 [inline] RIP: 0010:obj_to_index include/linux/slub_def.h:191 [inline] RIP: 0010:memcg_slab_free_hook+0x120/0x260 mm/slab.h:363 [...] Call Trace: kmem_cache_free_bulk+0x58/0x630 mm/slub.c:3293 kfree_bulk include/linux/slab.h:413 [inline] kfree_rcu_work+0x1ab/0x200 kernel/rcu/tree.c:3300 process_one_work+0x207/0x530 kernel/workqueue.c:2276 worker_thread+0x320/0x610 kernel/workqueue.c:2422 kthread+0x13d/0x160 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 When kmalloc_node() a large memory, page is allocated, not slab, so when freeing memory via kfree_rcu(), this large memory should not be used by memcg_slab_free_hook(), because memcg_slab_free_hook() is is used for slab. Using page_objcgs_check() instead of page_objcgs() in memcg_slab_free_hook() to fix this bug. Link: https://lkml.kernel.org/r/20210728145655.274476-1-wanghai38@huawei.com Fixes: 270c6a71460e ("mm: memcontrol/slab: Use helpers to access slab page's memcg_data") Signed-off-by: Wang Hai <wanghai38@huawei.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Roman Gushchin <guro@fb.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-15mm: move helper to check slub_debug_enabledMarco Elver1-4/+11
Move the helper to check slub_debug_enabled, so that we can confine the use of #ifdef outside slub.c as well. Link: https://lkml.kernel.org/r/20210705103229.8505-2-yee.lee@mediatek.com Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Yee Lee <yee.lee@mediatek.com> Suggested-by: Matthew Wilcox <willy@infradead.org> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Chinwen Chang <chinwen.chang@mediatek.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> Cc: Nicholas Tang <nicholas.tang@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-04Merge branch 'core-rcu-2021.07.04' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu Pull RCU updates from Paul McKenney: - Bitmap parsing support for "all" as an alias for all bits - Documentation updates - Miscellaneous fixes, including some that overlap into mm and lockdep - kvfree_rcu() updates - mem_dump_obj() updates, with acks from one of the slab-allocator maintainers - RCU NOCB CPU updates, including limited deoffloading - SRCU updates - Tasks-RCU updates - Torture-test updates * 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (78 commits) tasks-rcu: Make show_rcu_tasks_gp_kthreads() be static inline rcu-tasks: Make ksoftirqd provide RCU Tasks quiescent states rcu: Add missing __releases() annotation rcu: Remove obsolete rcu_read_unlock() deadlock commentary rcu: Improve comments describing RCU read-side critical sections rcu: Create an unrcu_pointer() to remove __rcu from a pointer srcu: Early test SRCU polling start rcu: Fix various typos in comments rcu/nocb: Unify timers rcu/nocb: Prepare for fine-grained deferred wakeup rcu/nocb: Only cancel nocb timer if not polling rcu/nocb: Delete bypass_timer upon nocb_gp wakeup rcu/nocb: Cancel nocb_timer upon nocb_gp wakeup rcu/nocb: Allow de-offloading rdp leader rcu/nocb: Directly call __wake_nocb_gp() from bypass timer rcu: Don't penalize priority boosting when there is nothing to boost rcu: Point to documentation of ordering guarantees rcu: Make rcu_gp_cleanup() be noinline for tracing rcu: Restrict RCU_STRICT_GRACE_PERIOD to at most four CPUs rcu: Make show_rcu_gp_kthreads() dump rcu_node structures blocking GP ...
2021-06-29mm: memcg/slab: properly set up gfp flags for objcg pointer arrayWaiman Long1-1/+0
Patch series "mm: memcg/slab: Fix objcg pointer array handling problem", v4. Since the merging of the new slab memory controller in v5.9, the page structure stores a pointer to objcg pointer array for slab pages. When the slab has no used objects, it can be freed in free_slab() which will call kfree() to free the objcg pointer array in memcg_alloc_page_obj_cgroups(). If it happens that the objcg pointer array is the last used object in its slab, that slab may then be freed which may caused kfree() to be called again. With the right workload, the slab cache may be set up in a way that allows the recursive kfree() calling loop to nest deep enough to cause a kernel stack overflow and panic the system. In fact, we have a reproducer that can cause kernel stack overflow on a s390 system involving kmalloc-rcl-256 and kmalloc-rcl-128 slabs with the following kfree() loop recursively called 74 times: [ 285.520739] [<000000000ec432fc>] kfree+0x4bc/0x560 [ 285.520740] [<000000000ec43466>] __free_slab+0xc6/0x228 [ 285.520741] [<000000000ec41fc2>] __slab_free+0x3c2/0x3e0 [ 285.520742] [<000000000ec432fc>] kfree+0x4bc/0x560 : While investigating this issue, I also found an issue on the allocation side. If the objcg pointer array happen to come from the same slab or a circular dependency linkage is formed with multiple slabs, those affected slabs can never be freed again. This patch series addresses these two issues by introducing a new set of kmalloc-cg-<n> caches split from kmalloc-<n> caches. The new set will only contain non-reclaimable and non-dma objects that are accounted in memory cgroups whereas the old set are now for unaccounted objects only. By making this split, all the objcg pointer arrays will come from the kmalloc-<n> caches, but those caches will never hold any objcg pointer array. As a result, deeply nested kfree() call and the unfreeable slab problems are now gone. This patch (of 4): Since the merging of the new slab memory controller in v5.9, the page structure may store a pointer to obj_cgroup pointer array for slab pages. Currently, only the __GFP_ACCOUNT bit is masked off. However, the array is not readily reclaimable and doesn't need to come from the DMA buffer. So those GFP bits should be masked off as well. Do the flag bit clearing at memcg_alloc_page_obj_cgroups() to make sure that it is consistently applied no matter where it is called. Link: https://lkml.kernel.org/r/20210505200610.13943-1-longman@redhat.com Link: https://lkml.kernel.org/r/20210505200610.13943-2-longman@redhat.com Fixes: 286e04b8ed7a ("mm: memcg/slab: allocate obj_cgroups for non-root slab pages") Signed-off-by: Waiman Long <longman@redhat.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Roman Gushchin <guro@fb.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29mm/memcg: move mod_objcg_state() to memcontrol.cWaiman Long1-14/+2
Patch series "mm/memcg: Reduce kmemcache memory accounting overhead", v6. With the recent introduction of the new slab memory controller, we eliminate the need for having separate kmemcaches for each memory cgroup and reduce overall kernel memory usage. However, we also add additional memory accounting overhead to each call of kmem_cache_alloc() and kmem_cache_free(). For workloads that require a lot of kmemcache allocations and de-allocations, they may experience performance regression as illustrated in [1] and [2]. A simple kernel module that performs repeated loop of 100,000,000 kmem_cache_alloc() and kmem_cache_free() of either a small 32-byte object or a big 4k object at module init time with a batch size of 4 (4 kmalloc's followed by 4 kfree's) is used for benchmarking. The benchmarking tool was run on a kernel based on linux-next-20210419. The test was run on a CascadeLake server with turbo-boosting disable to reduce run-to-run variation. The small object test exercises mainly the object stock charging and vmstat update code paths. The large object test also exercises the refill_obj_stock() and __memcg_kmem_charge()/__memcg_kmem_uncharge() code paths. With memory accounting disabled, the run time was 3.130s with both small object big object tests. With memory accounting enabled, both cgroup v1 and v2 showed similar results in the small object test. The performance results of the large object test, however, differed between cgroup v1 and v2. The execution times with the application of various patches in the patchset were: Applied patches Run time Accounting overhead %age 1 %age 2 --------------- -------- ------------------- ------ ------ Small 32-byte object: None 11.634s 8.504s 100.0% 271.7% 1-2 9.425s 6.295s 74.0% 201.1% 1-3 9.708s 6.578s 77.4% 210.2% 1-4 8.062s 4.932s 58.0% 157.6% Large 4k object (v2): None 22.107s 18.977s 100.0% 606.3% 1-2 20.960s 17.830s 94.0% 569.6% 1-3 14.238s 11.108s 58.5% 354.9% 1-4 11.329s 8.199s 43.2% 261.9% Large 4k object (v1): None 36.807s 33.677s 100.0% 1075.9% 1-2 36.648s 33.518s 99.5% 1070.9% 1-3 22.345s 19.215s 57.1% 613.9% 1-4 18.662s 15.532s 46.1% 496.2% N.B. %age 1 = overhead/unpatched overhead %age 2 = overhead/accounting disabled time Patch 2 (vmstat data stock caching) helps in both the small object test and the large v2 object test. It doesn't help much in v1 big object test. Patch 3 (refill_obj_stock improvement) does help the small object test but offer significant performance improvement for the large object test (both v1 and v2). Patch 4 (eliminating irq disable/enable) helps in all test cases. To test for the extreme case, a multi-threaded kmalloc/kfree microbenchmark was run on the 2-socket 48-core 96-thread system with 96 testing threads in the same memcg doing kmalloc+kfree of a 4k object with accounting enabled for 10s. The total number of kmalloc+kfree done in kilo operations per second (kops/s) were as follows: Applied patches v1 kops/s v1 change v2 kops/s v2 change --------------- --------- --------- --------- --------- None 3,520 1.00X 6,242 1.00X 1-2 4,304 1.22X 8,478 1.36X 1-3 4,731 1.34X 418,142 66.99X 1-4 4,587 1.30X 438,838 70.30X With memory accounting disabled, the kmalloc/kfree rate was 1,481,291 kop/s. This test shows how significant the memory accouting overhead can be in some extreme situations. For this multithreaded test, the improvement from patch 2 mainly comes from the conditional atomic xchg of objcg->nr_charged_bytes in mod_objcg_state(). By using an unconditional xchg, the operation rates were similar to the unpatched kernel. Patch 3 elminates the single highly contended cacheline of objcg->nr_charged_bytes for cgroup v2 leading to a huge performance improvement. Cgroup v1, however, still has another highly contended cacheline in the shared page counter &memcg->kmem. So the improvement is only modest. Patch 4 helps in cgroup v2, but performs worse in cgroup v1 as eliminating the irq_disable/irq_enable overhead seems to aggravate the cacheline contention. [1] https://lore.kernel.org/linux-mm/20210408193948.vfktg3azh2wrt56t@gabell/T/#u [2] https://lore.kernel.org/lkml/20210114025151.GA22932@xsang-OptiPlex-9020/ This patch (of 4): mod_objcg_state() is moved from mm/slab.h to mm/memcontrol.c so that further optimization can be done to it in later patches without exposing unnecessary details to other mm components. Link: https://lkml.kernel.org/r/20210506150007.16288-1-longman@redhat.com Link: https://lkml.kernel.org/r/20210506150007.16288-2-longman@redhat.com Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Roman Gushchin <guro@fb.com> Cc: Alex Shi <alex.shi@linux.alibaba.com> Cc: Chris Down <chris@chrisdown.name> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Masayoshi Mizuma <msys.mizuma@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com> Cc: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29mm: slub: move sysfs slab alloc/free interfaces to debugfsFaiyaz Mohammed1-0/+6
alloc_calls and free_calls implementation in sysfs have two issues, one is PAGE_SIZE limitation of sysfs and other is it does not adhere to "one value per file" rule. To overcome this issues, move the alloc_calls and free_calls implementation to debugfs. Debugfs cache will be created if SLAB_STORE_USER flag is set. Rename the alloc_calls/free_calls to alloc_traces/free_traces, to be inline with what it does. [faiyazm@codeaurora.org: fix the leak of alloc/free traces debugfs interface] Link: https://lkml.kernel.org/r/1624248060-30286-1-git-send-email-faiyazm@codeaurora.org Link: https://lkml.kernel.org/r/1623438200-19361-1-git-send-email-faiyazm@codeaurora.org Signed-off-by: Faiyaz Mohammed <faiyazm@codeaurora.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29mm/slub, kunit: add a KUnit test for SLUB debugging functionalityOliver Glitta1-0/+1
SLUB has resiliency_test() function which is hidden behind #ifdef SLUB_RESILIENCY_TEST that is not part of Kconfig, so nobody runs it. KUnit should be a proper replacement for it. Try changing byte in redzone after allocation and changing pointer to next free node, first byte, 50th byte and redzone byte. Check if validation finds errors. There are several differences from the original resiliency test: Tests create own caches with known state instead of corrupting shared kmalloc caches. The corruption of freepointer uses correct offset, the original resiliency test got broken with freepointer changes. Scratch changing random byte test, because it does not have meaning in this form where we need deterministic results. Add new option CONFIG_SLUB_KUNIT_TEST in Kconfig. Tests next_pointer, first_word and clobber_50th_byte do not run with KASAN option on. Because the test deliberately modifies non-allocated objects. Use kunit_resource to count errors in cache and silence bug reports. Count error whenever slab_bug() or slab_fix() is called or when the count of pages is wrong. [glittao@gmail.com: remove unused function test_exit(), from SLUB KUnit test] Link: https://lkml.kernel.org/r/20210512140656.12083-1-glittao@gmail.com [akpm@linux-foundation.org: export kasan_enable/disable_current to modules] Link: https://lkml.kernel.org/r/20210511150734.3492-2-glittao@gmail.com Signed-off-by: Oliver Glitta <glittao@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Daniel Latypov <dlatypov@google.com> Acked-by: Marco Elver <elver@google.com> Cc: Brendan Higgins <brendanhiggins@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-10mm/slub: Add Support for free path information of an objectManinder Singh1-0/+1
This commit adds enables a stack dump for the last free of an object: slab kmalloc-64 start c8ab0140 data offset 64 pointer offset 0 size 64 allocated at meminfo_proc_show+0x40/0x4fc [ 20.192078] meminfo_proc_show+0x40/0x4fc [ 20.192263] seq_read_iter+0x18c/0x4c4 [ 20.192430] proc_reg_read_iter+0x84/0xac [ 20.192617] generic_file_splice_read+0xe8/0x17c [ 20.192816] splice_direct_to_actor+0xb8/0x290 [ 20.193008] do_splice_direct+0xa0/0xe0 [ 20.193185] do_sendfile+0x2d0/0x438 [ 20.193345] sys_sendfile64+0x12c/0x140 [ 20.193523] ret_fast_syscall+0x0/0x58 [ 20.193695] 0xbeeacde4 [ 20.193822] Free path: [ 20.193935] meminfo_proc_show+0x5c/0x4fc [ 20.194115] seq_read_iter+0x18c/0x4c4 [ 20.194285] proc_reg_read_iter+0x84/0xac [ 20.194475] generic_file_splice_read+0xe8/0x17c [ 20.194685] splice_direct_to_actor+0xb8/0x290 [ 20.194870] do_splice_direct+0xa0/0xe0 [ 20.195014] do_sendfile+0x2d0/0x438 [ 20.195174] sys_sendfile64+0x12c/0x140 [ 20.195336] ret_fast_syscall+0x0/0x58 [ 20.195491] 0xbeeacde4 Acked-by: Vlastimil Babka <vbabka@suse.cz> Co-developed-by: Vaneet Narang <v.narang@samsung.com> Signed-off-by: Vaneet Narang <v.narang@samsung.com> Signed-off-by: Maninder Singh <maninder1.s@samsung.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-04-30kasan, mm: integrate slab init_on_alloc with HW_TAGSAndrey Konovalov1-4/+13
This change uses the previously added memory initialization feature of HW_TAGS KASAN routines for slab memory when init_on_alloc is enabled. With this change, memory initialization memset() is no longer called when both HW_TAGS KASAN and init_on_alloc are enabled. Instead, memory is initialized in KASAN runtime. The memory initialization memset() is moved into slab_post_alloc_hook() that currently directly follows the initialization loop. A new argument is added to slab_post_alloc_hook() that indicates whether to initialize the memory or not. To avoid discrepancies with which memory gets initialized that can be caused by future changes, both KASAN hook and initialization memset() are put together and a warning comment is added. Combining setting allocation tags with memory initialization improves HW_TAGS KASAN performance when init_on_alloc is enabled. Link: https://lkml.kernel.org/r/c1292aeb5d519da221ec74a0684a949b027d7720.1615296150.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-28Merge tag 'core-rcu-2021-04-28' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: - Support for "N" as alias for last bit in bitmap parsing library (eg using syntax like "nohz_full=2-N") - kvfree_rcu updates - mm_dump_obj() updates. (One of these is to mm, but was suggested by Andrew Morton.) - RCU callback offloading update - Polling RCU grace-period interfaces - Realtime-related RCU updates - Tasks-RCU updates - Torture-test updates - Torture-test scripting updates - Miscellaneous fixes * tag 'core-rcu-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (77 commits) rcutorture: Test start_poll_synchronize_rcu() and poll_state_synchronize_rcu() rcu: Provide polling interfaces for Tiny RCU grace periods torture: Fix kvm.sh --datestamp regex check torture: Consolidate qemu-cmd duration editing into kvm-transform.sh torture: Print proper vmlinux path for kvm-again.sh runs torture: Make TORTURE_TRUST_MAKE available in kvm-again.sh environment torture: Make kvm-transform.sh update jitter commands torture: Add --duration argument to kvm-again.sh torture: Add kvm-again.sh to rerun a previous torture-test torture: Create a "batches" file for build reuse torture: De-capitalize TORTURE_SUITE torture: Make upper-case-only no-dot no-slash scenario names official torture: Rename SRCU-t and SRCU-u to avoid lowercase characters torture: Remove no-mpstat error message torture: Record kvm-test-1-run.sh and kvm-test-1-run-qemu.sh PIDs torture: Record jitter start/stop commands torture: Extract kvm-test-1-run-qemu.sh from kvm-test-1-run.sh torture: Record TORTURE_KCONFIG_GDB_ARG in qemu-cmd torture: Abstract jitter.sh start/stop into scripts rcu: Provide polling interfaces for Tree RCU grace periods ...
2021-04-08init_on_alloc: Optimize static branchesKees Cook1-2/+4
The state of CONFIG_INIT_ON_ALLOC_DEFAULT_ON (and ...ON_FREE...) did not change the assembly ordering of the static branches: they were always out of line. Use the new jump_label macros to check the CONFIG settings to default to the "expected" state, which slightly optimizes the resulting assembly code. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexander Potapenko <glider@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Link: https://lore.kernel.org/r/20210401232347.2791257-3-keescook@chromium.org
2021-03-08mm: Don't build mm_dump_obj() on CONFIG_PRINTK=n kernelsPaul E. McKenney1-0/+2
The mem_dump_obj() functionality adds a few hundred bytes, which is a small price to pay. Except on kernels built with CONFIG_PRINTK=n, in which mem_dump_obj() messages will be suppressed. This commit therefore makes mem_dump_obj() be a static inline empty function on kernels built with CONFIG_PRINTK=n and excludes all of its support functions as well. This avoids kernel bloat on systems that cannot use mem_dump_obj(). Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: <linux-mm@kvack.org> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-02-24mm: memcg/slab: pre-allocate obj_cgroups for slab caches with SLAB_ACCOUNTRoman Gushchin1-4/+10
In general it's unknown in advance if a slab page will contain accounted objects or not. In order to avoid memory waste, an obj_cgroup vector is allocated dynamically when a need to account of a new object arises. Such approach is memory efficient, but requires an expensive cmpxchg() to set up the memcg/objcgs pointer, because an allocation can race with a different allocation on another cpu. But in some common cases it's known for sure that a slab page will contain accounted objects: if the page belongs to a slab cache with a SLAB_ACCOUNT flag set. It includes such popular objects like vm_area_struct, anon_vma, task_struct, etc. In such cases we can pre-allocate the objcgs vector and simple assign it to the page without any atomic operations, because at this early stage the page is not visible to anyone else. A very simplistic benchmark (allocating 10000000 64-bytes objects in a row) shows ~15% win. In the real life it seems that most workloads are not very sensitive to the speed of (accounted) slab allocations. [guro@fb.com: open-code set_page_objcgs() and add some comments, by Johannes] Link: https://lkml.kernel.org/r/20201113001926.GA2934489@carbon.dhcp.thefacebook.com [akpm@linux-foundation.org: fix it for mm-slub-call-account_slab_page-after-slab-page-initialization-fix.patch] Link: https://lkml.kernel.org/r/20201110195753.530157-2-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-24mm/sl?b.c: remove ctor argument from kmem_cache_flagsNikolay Borisov1-4/+2
This argument hasn't been used since e153362a50a3 ("slub: Remove objsize check in kmem_cache_flags()") so simply remove it. Link: https://lkml.kernel.org/r/20210126095733.974665-1-nborisov@suse.com Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-22mm: Add mem_dump_obj() to print source of memory blockPaul E. McKenney1-0/+12
There are kernel facilities such as per-CPU reference counts that give error messages in generic handlers or callbacks, whose messages are unenlightening. In the case of per-CPU reference-count underflow, this is not a problem when creating a new use of this facility because in that case the bug is almost certainly in the code implementing that new use. However, trouble arises when deploying across many systems, which might exercise corner cases that were not seen during development and testing. Here, it would be really nice to get some kind of hint as to which of several uses the underflow was caused by. This commit therefore exposes a mem_dump_obj() function that takes a pointer to memory (which must still be allocated if it has been dynamically allocated) and prints available information on where that memory came from. This pointer can reference the middle of the block as well as the beginning of the block, as needed by things like RCU callback functions and timer handlers that might not know where the beginning of the memory block is. These functions and handlers can use mem_dump_obj() to print out better hints as to where the problem might lie. The information printed can depend on kernel configuration. For example, the allocation return address can be printed only for slab and slub, and even then only when the necessary debug has been enabled. For slab, build with CONFIG_DEBUG_SLAB=y, and either use sizes with ample space to the next power of two or use the SLAB_STORE_USER when creating the kmem_cache structure. For slub, build with CONFIG_SLUB_DEBUG=y and boot with slub_debug=U, or pass SLAB_STORE_USER to kmem_cache_create() if more focused use is desired. Also for slub, use CONFIG_STACKTRACE to enable printing of the allocation-time stack trace. Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <linux-mm@kvack.org> Reported-by: Andrii Nakryiko <andrii@kernel.org> [ paulmck: Convert to printing and change names per Joonsoo Kim. ] [ paulmck: Move slab definition per Stephen Rothwell and kbuild test robot. ] [ paulmck: Handle CONFIG_MMU=n case where vmalloc() is kmalloc(). ] [ paulmck: Apply Vlastimil Babka feedback on slab.c kmem_provenance(). ] [ paulmck: Extract more info from !SLUB_DEBUG per Joonsoo Kim. ] [ paulmck: Explicitly check for small pointers per Naresh Kamboju. ] Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-12-15Merge tag 'net-next-5.11' of ↵Linus Torvalds1-29/+9
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core: - support "prefer busy polling" NAPI operation mode, where we defer softirq for some time expecting applications to periodically busy poll - AF_XDP: improve efficiency by more batching and hindering the adjacency cache prefetcher - af_packet: make packet_fanout.arr size configurable up to 64K - tcp: optimize TCP zero copy receive in presence of partial or unaligned reads making zero copy a performance win for much smaller messages - XDP: add bulk APIs for returning / freeing frames - sched: support fragmenting IP packets as they come out of conntrack - net: allow virtual netdevs to forward UDP L4 and fraglist GSO skbs BPF: - BPF switch from crude rlimit-based to memcg-based memory accounting - BPF type format information for kernel modules and related tracing enhancements - BPF implement task local storage for BPF LSM - allow the FENTRY/FEXIT/RAW_TP tracing programs to use bpf_sk_storage Protocols: - mptcp: improve multiple xmit streams support, memory accounting and many smaller improvements - TLS: support CHACHA20-POLY1305 cipher - seg6: add support for SRv6 End.DT4/DT6 behavior - sctp: Implement RFC 6951: UDP Encapsulation of SCTP - ppp_generic: add ability to bridge channels directly - bridge: Connectivity Fault Management (CFM) support as is defined in IEEE 802.1Q section 12.14. Drivers: - mlx5: make use of the new auxiliary bus to organize the driver internals - mlx5: more accurate port TX timestamping support - mlxsw: - improve the efficiency of offloaded next hop updates by using the new nexthop object API - support blackhole nexthops - support IEEE 802.1ad (Q-in-Q) bridging - rtw88: major bluetooth co-existance improvements - iwlwifi: support new 6 GHz frequency band - ath11k: Fast Initial Link Setup (FILS) - mt7915: dual band concurrent (DBDC) support - net: ipa: add basic support for IPA v4.5 Refactor: - a few pieces of in_interrupt() cleanup work from Sebastian Andrzej Siewior - phy: add support for shared interrupts; get rid of multiple driver APIs and have the drivers write a full IRQ handler, slight growth of driver code should be compensated by the simpler API which also allows shared IRQs - add common code for handling netdev per-cpu counters - move TX packet re-allocation from Ethernet switch tag drivers to a central place - improve efficiency and rename nla_strlcpy - number of W=1 warning cleanups as we now catch those in a patchwork build bot Old code removal: - wan: delete the DLCI / SDLA drivers - wimax: move to staging - wifi: remove old WDS wifi bridging support" * tag 'net-next-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1922 commits) net: hns3: fix expression that is currently always true net: fix proc_fs init handling in af_packet and tls nfc: pn533: convert comma to semicolon af_vsock: Assign the vsock transport considering the vsock address flags af_vsock: Set VMADDR_FLAG_TO_HOST flag on the receive path vsock_addr: Check for supported flag values vm_sockets: Add VMADDR_FLAG_TO_HOST vsock flag vm_sockets: Add flags field in the vsock address data structure net: Disable NETIF_F_HW_TLS_TX when HW_CSUM is disabled tcp: Add logic to check for SYN w/ data in tcp_simple_retransmit net: mscc: ocelot: install MAC addresses in .ndo_set_rx_mode from process context nfc: s3fwrn5: Release the nfc firmware net: vxget: clean up sparse warnings mlxsw: spectrum_router: Use eXtended mezzanine to offload IPv4 router mlxsw: spectrum: Set KVH XLT cache mode for Spectrum2/3 mlxsw: spectrum_router_xm: Introduce basic XM cache flushing mlxsw: reg: Add Router LPM Cache Enable Register mlxsw: reg: Add Router LPM Cache ML Delete Register mlxsw: spectrum_router_xm: Implement L-value tracking for M-index mlxsw: reg: Add XM Router M Table Register ...
2020-12-15mm: extract might_alloc() debug checkDaniel Vetter1-4/+1
Extracted from slab.h, which seems to have the most complete version including the correct might_sleep() check. Roll it out to slob.c. Motivated by a discussion with Paul about possibly changing call_rcu behaviour to allocate memory, but only roughly every 500th call. There are a lot fewer places in the kernel that care about whether allocating memory is allowed or not (due to deadlocks with reclaim code) than places that care whether sleeping is allowed. But debugging these also tends to be a lot harder, so nice descriptive checks could come in handy. I might have some use eventually for annotations in drivers/gpu. Note that unlike fs_reclaim_acquire/release gfpflags_allow_blocking does not consult the PF_MEMALLOC flags. But there is no flag equivalent for GFP_NOWAIT, hence this check can't go wrong due to memalloc_no*_save/restore contexts. Willy is working on a patch series which might change this: https://lore.kernel.org/linux-mm/20200625113122.7540-7-willy@infradead.org/ I think best would be if that updates gfpflags_allow_blocking(), since there's a ton of callers all over the place for that already. Link: https://lkml.kernel.org/r/20201125162532.1299794-3-daniel.vetter@ffwll.ch Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Michel Lespinasse <walken@google.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Waiman Long <longman@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Qian Cai <cai@lca.pw> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Christian König <christian.koenig@amd.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Thomas Hellström (Intel) <thomas_os@shipmail.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-15mm: memcontrol: remove unused mod_memcg_obj_state()Muchun Song1-2/+2
Since commit 991e7673859e ("mm: memcontrol: account kernel stack per node") there is no user of the mod_memcg_obj_state(). So just remove it. Also rework type of the idx parameter of the mod_objcg_state() from int to enum node_stat_item. Link: https://lkml.kernel.org/r/20201013153504.92602-1-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Roman Gushchin <guro@fb.com> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Christopher Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yafang Shao <laoar.shao@gmail.com> Cc: Chris Down <chris@chrisdown.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-16/+24
xdp_return_frame_bulk() needs to pass a xdp_buff to __xdp_return(). strlcpy got converted to strscpy but here it makes no functional difference, so just keep the right code. Conflicts: net/netfilter/nf_tables_api.c Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-06mm: memcg/slab: fix obj_cgroup_charge() return value handlingRoman Gushchin1-16/+24
Commit 10befea91b61 ("mm: memcg/slab: use a single set of kmem_caches for all allocations") introduced a regression into the handling of the obj_cgroup_charge() return value. If a non-zero value is returned (indicating of exceeding one of memory.max limits), the allocation should fail, instead of falling back to non-accounted mode. To make the code more readable, move memcg_slab_pre_alloc_hook() and memcg_slab_post_alloc_hook() calling conditions into bodies of these hooks. Fixes: 10befea91b61 ("mm: memcg/slab: use a single set of kmem_caches for all allocations") Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201127161828.GD840171@carbon.dhcp.thefacebook.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-02mm: memcontrol/slab: Use helpers to access slab page's memcg_dataRoman Gushchin1-27/+8
To gather all direct accesses to struct page's memcg_data field in one place, let's introduce 3 new helpers to use in the slab accounting code: struct obj_cgroup **page_objcgs(struct page *page); struct obj_cgroup **page_objcgs_check(struct page *page); bool set_page_objcgs(struct page *page, struct obj_cgroup **objcgs); They are similar to the corresponding API for generic pages, except that the setter can return false, indicating that the value has been already set from a different thread. Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Link: https://lkml.kernel.org/r/20201027001657.3398190-3-guro@fb.com Link: https://lore.kernel.org/bpf/20201201215900.3569844-3-guro@fb.com
2020-12-02mm: memcontrol: Use helpers to read page's memcg dataRoman Gushchin1-5/+4
Patch series "mm: allow mapping accounted kernel pages to userspace", v6. Currently a non-slab kernel page which has been charged to a memory cgroup can't be mapped to userspace. The underlying reason is simple: PageKmemcg flag is defined as a page type (like buddy, offline, etc), so it takes a bit from a page->mapped counter. Pages with a type set can't be mapped to userspace. But in general the kmemcg flag has nothing to do with mapping to userspace. It only means that the page has been accounted by the page allocator, so it has to be properly uncharged on release. Some bpf maps are mapping the vmalloc-based memory to userspace, and their memory can't be accounted because of this implementation detail. This patchset removes this limitation by moving the PageKmemcg flag into one of the free bits of the page->mem_cgroup pointer. Also it formalizes accesses to the page->mem_cgroup and page->obj_cgroups using new helpers, adds several checks and removes a couple of obsolete functions. As the result the code became more robust with fewer open-coded bit tricks. This patch (of 4): Currently there are many open-coded reads of the page->mem_cgroup pointer, as well as a couple of read helpers, which are barely used. It creates an obstacle on a way to reuse some bits of the pointer for storing additional bits of information. In fact, we already do this for slab pages, where the last bit indicates that a pointer has an attached vector of objcg pointers instead of a regular memcg pointer. This commits uses 2 existing helpers and introduces a new helper to converts all read sides to calls of these helpers: struct mem_cgroup *page_memcg(struct page *page); struct mem_cgroup *page_memcg_rcu(struct page *page); struct mem_cgroup *page_memcg_check(struct page *page); page_memcg_check() is intended to be used in cases when the page can be a slab page and have a memcg pointer pointing at objcg vector. It does check the lowest bit, and if set, returns NULL. page_memcg() contains a VM_BUG_ON_PAGE() check for the page not being a slab page. To make sure nobody uses a direct access, struct page's mem_cgroup/obj_cgroups is converted to unsigned long memcg_data. Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Link: https://lkml.kernel.org/r/20201027001657.3398190-1-guro@fb.com Link: https://lkml.kernel.org/r/20201027001657.3398190-2-guro@fb.com Link: https://lore.kernel.org/bpf/20201201215900.3569844-2-guro@fb.com
2020-10-18mm: kmem: move memcg_kmem_bypass() calls to get_mem/obj_cgroup_from_current()Roman Gushchin1-3/+0
Patch series "mm: kmem: kernel memory accounting in an interrupt context". This patchset implements memcg-based memory accounting of allocations made from an interrupt context. Historically, such allocations were passed unaccounted mostly because charging the memory cgroup of the current process wasn't an option. Also performance reasons were likely a reason too. The remote charging API allows to temporarily overwrite the currently active memory cgroup, so that all memory allocations are accounted towards some specified memory cgroup instead of the memory cgroup of the current process. This patchset extends the remote charging API so that it can be used from an interrupt context. Then it removes the fence that prevented the accounting of allocations made from an interrupt context. It also contains a couple of optimizations/code refactorings. This patchset doesn't directly enable accounting for any specific allocations, but prepares the code base for it. The bpf memory accounting will likely be the first user of it: a typical example is a bpf program parsing an incoming network packet, which allocates an entry in hashmap map to store some information. This patch (of 4): Currently memcg_kmem_bypass() is called before obtaining the current memory/obj cgroup using get_mem/obj_cgroup_from_current(). Moving memcg_kmem_bypass() into get_mem/obj_cgroup_from_current() reduces the number of call sites and allows further code simplifications. Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Link: http://lkml.kernel.org/r/20200827225843.1270629-1-guro@fb.com Link: http://lkml.kernel.org/r/20200827225843.1270629-2-guro@fb.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16mm/slab.h: remove duplicate includeYueHaibing1-1/+0
Remove duplicate header which is included twice. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Pekka Enberg <penberg@kernel.org> Link: http://lkml.kernel.org/r/20200818114323.58156-1-yuehaibing@huawei.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13mm: memcg/slab: uncharge during kmem_cache_free_bulk()Bharata B Rao1-15/+27
Object cgroup charging is done for all the objects during allocation, but during freeing, uncharging ends up happening for only one object in the case of bulk allocation/freeing. Fix this by having a separate call to uncharge all the objects from kmem_cache_free_bulk() and by modifying memcg_slab_free_hook() to take care of bulk uncharging. Fixes: 964d4bd370d5 ("mm: memcg/slab: save obj_cgroup for non-root slab objects" Signed-off-by: Bharata B Rao <bharata@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Roman Gushchin <guro@fb.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Shakeel Butt <shakeelb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201009060423.390479-1-bharata@linux.ibm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm: slab: rename (un)charge_slab_page() to (un)account_slab_page()Roman Gushchin1-4/+4
charge_slab_page() and uncharge_slab_page() are not related anymore to memcg charging and uncharging. In order to make their names less confusing, let's rename them to account_slab_page() and unaccount_slab_page() respectively. Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Link: http://lkml.kernel.org/r/20200707173612.124425-2-guro@fb.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm: memcg/slab: remove unused argument by charge_slab_page()Roman Gushchin1-2/+1
charge_slab_page() is not using the gfp argument anymore, remove it. Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Link: http://lkml.kernel.org/r/20200707173612.124425-1-guro@fb.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm: memcg/slab: use a single set of kmem_caches for all allocationsRoman Gushchin1-152/+42
Instead of having two sets of kmem_caches: one for system-wide and non-accounted allocations and the second one shared by all accounted allocations, we can use just one. The idea is simple: space for obj_cgroup metadata can be allocated on demand and filled only for accounted allocations. It allows to remove a bunch of code which is required to handle kmem_cache clones for accounted allocations. There is no more need to create them, accumulate statistics, propagate attributes, etc. It's a quite significant simplification. Also, because the total number of slab_caches is reduced almost twice (not all kmem_caches have a memcg clone), some additional memory savings are expected. On my devvm it additionally saves about 3.5% of slab memory. [guro@fb.com: fix build on MIPS] Link: http://lkml.kernel.org/r/20200717214810.3733082-1-guro@fb.com Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Link: http://lkml.kernel.org/r/20200623174037.3951353-18-guro@fb.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm: memcg/slab: deprecate slab_root_cachesRoman Gushchin1-17/+0
Currently there are two lists of kmem_caches: 1) slab_caches, which contains all kmem_caches, 2) slab_root_caches, which contains only root kmem_caches. And there is some preprocessor magic to have a single list if CONFIG_MEMCG_KMEM isn't enabled. It was required earlier because the number of non-root kmem_caches was proportional to the number of memory cgroups and could reach really big values. Now, when it cannot exceed the number of root kmem_caches, there is really no reason to maintain two lists. We never iterate over the slab_root_caches list on any hot paths, so it's perfectly fine to iterate over slab_caches and filter out non-root kmem_caches. It allows to remove a lot of config-dependent code and two pointers from the kmem_cache structure. Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/20200623174037.3951353-16-guro@fb.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm: memcg/slab: remove memcg_kmem_get_cache()Roman Gushchin1-2/+9
The memcg_kmem_get_cache() function became really trivial, so let's just inline it into the single call point: memcg_slab_pre_alloc_hook(). It will make the code less bulky and can also help the compiler to generate a better code. Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/20200623174037.3951353-15-guro@fb.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm: memcg/slab: simplify memcg cache creationRoman Gushchin1-0/+2
Because the number of non-root kmem_caches doesn't depend on the number of memory cgroups anymore and is generally not very big, there is no more need for a dedicated workqueue. Also, as there is no more need to pass any arguments to the memcg_create_kmem_cache() except the root kmem_cache, it's possible to just embed the work structure into the kmem_cache and avoid the dynamic allocation of the work structure. This will also simplify the synchronization: for each root kmem_cache there is only one work. So there will be no more concurrent attempts to create a non-root kmem_cache for a root kmem_cache: the second and all following attempts to queue the work will fail. On the kmem_cache destruction path there is no more need to call the expensive flush_workqueue() and wait for all pending works to be finished. Instead, cancel_work_sync() can be used to cancel/wait for only one work. Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/20200623174037.3951353-14-guro@fb.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm: memcg/slab: use a single set of kmem_caches for all accounted allocationsRoman Gushchin1-101/+45
This is fairly big but mostly red patch, which makes all accounted slab allocations use a single set of kmem_caches instead of creating a separate set for each memory cgroup. Because the number of non-root kmem_caches is now capped by the number of root kmem_caches, there is no need to shrink or destroy them prematurely. They can be perfectly destroyed together with their root counterparts. This allows to dramatically simplify the management of non-root kmem_caches and delete a ton of code. This patch performs the following changes: 1) introduces memcg_params.memcg_cache pointer to represent the kmem_cache which will be used for all non-root allocations 2) reuses the existing memcg kmem_cache creation mechanism to create memcg kmem_cache on the first allocation attempt 3) memcg kmem_caches are named <kmemcache_name>-memcg, e.g. dentry-memcg 4) simplifies memcg_kmem_get_cache() to just return memcg kmem_cache or schedule it's creation and return the root cache 5) removes almost all non-root kmem_cache management code (separate refcounter, reparenting, shrinking, etc) 6) makes slab debugfs to display root_mem_cgroup css id and never show :dead and :deact flags in the memcg_slabinfo attribute. Following patches in the series will simplify the kmem_cache creation. Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/20200623174037.3951353-13-guro@fb.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>