mm: memcg/slab: uncharge during kmem_cache_free_bulk()

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>

1 files changed, 2 insertions, 1 deletions

diff --git a/mm/slub.c b/mm/slub.c
index f05900186c0b..61d0d2968413 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3095,7 +3095,7 @@ static __always_inline void do_slab_free(struct kmem_cache *s,
 	struct kmem_cache_cpu *c;
 	unsigned long tid;
 
-	memcg_slab_free_hook(s, page, head);
+	memcg_slab_free_hook(s, &head, 1);
 redo:
 	/*
 	 * Determine the currently cpus per cpu slab.
@@ -3257,6 +3257,7 @@ void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p)
 	if (WARN_ON(!size))
 		return;
 
+	memcg_slab_free_hook(s, p, size);
 	do {
 		struct detached_freelist df;