From: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: mm, slub: fix incorrect memcg slab count for bulk free kmem_cache_free_bulk() will call memcg_slab_free_hook() for all objects when doing bulk free. So we shouldn't call memcg_slab_free_hook() again for bulk free to avoid incorrect memcg slab count. Link: https://lkml.kernel.org/r/20210916123920.48704-6-linmiaohe@xxxxxxxxxx Fixes: d1b2cf6cb84a ("mm: memcg/slab: uncharge during kmem_cache_free_bulk()") Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx> Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> Cc: Bharata B Rao <bharata@xxxxxxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Faiyaz Mohammed <faiyazm@xxxxxxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Cc: Roman Gushchin <guro@xxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/slub.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/mm/slub.c~mm-slub-fix-incorrect-memcg-slab-count-for-bulk-free +++ a/mm/slub.c @@ -3420,7 +3420,9 @@ static __always_inline void do_slab_free struct kmem_cache_cpu *c; unsigned long tid; - memcg_slab_free_hook(s, &head, 1); + /* memcg_slab_free_hook() is already called for bulk free. */ + if (!tail) + memcg_slab_free_hook(s, &head, 1); redo: /* * Determine the currently cpus per cpu slab. _
