slub: fix off by one in number of slab tests
authorJoonsoo Kim <iamjoonsoo.kim@lge.com>
Wed, 2 Jul 2014 22:22:35 +0000 (15:22 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 3 Jul 2014 16:21:53 +0000 (09:21 -0700)
commit8a5b20aebaa3d0ade5b8381e64d35fb777b7b355
treeaec5b72a829413901bb0c1a03371f7dc2b84709a
parentdc78327c0ea7da5186d8cbc1647bd6088c5c9fa5
slub: fix off by one in number of slab tests

min_partial means minimum number of slab cached in node partial list.
So, if nr_partial is less than it, we keep newly empty slab on node
partial list rather than freeing it.  But if nr_partial is equal or
greater than it, it means that we have enough partial slabs so should
free newly empty slab.  Current implementation missed the equal case so
if we set min_partial is 0, then, at least one slab could be cached.
This is critical problem to kmemcg destroying logic because it doesn't
works properly if some slabs is cached.  This patch fixes this problem.

Fixes 91cb69620284 ("slub: make dead memcg caches discard free slabs
immediately").

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/slub.c