slub,rcu: don't assume the size of struct rcu_head
authorLai Jiangshan <laijs@cn.fujitsu.com>
Thu, 10 Mar 2011 07:22:00 +0000 (15:22 +0800)
committerPekka Enberg <penberg@kernel.org>
Fri, 11 Mar 2011 16:06:34 +0000 (18:06 +0200)
commitda9a638c6f8fc0633fa94a334f1c053f5e307177
tree786966087ccd4fd2c97757ce7b722f728c17ca2b
parentab9a0f196f2f4f080df54402493ea3dc31b5243e
slub,rcu: don't assume the size of struct rcu_head

The size of struct rcu_head may be changed. When it becomes larger,
it will pollute the page array.

We reserve some some bytes for struct rcu_head when a slab
is allocated in this situation.

Changed from V1:
use VM_BUG_ON instead BUG_ON

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
mm/slub.c