percpu: fix pcpu_reclaim() locking
authorTejun Heo <tj@kernel.org>
Fri, 14 Aug 2009 06:00:49 +0000 (15:00 +0900)
committerTejun Heo <tj@kernel.org>
Fri, 14 Aug 2009 06:00:49 +0000 (15:00 +0900)
commit971f3918a5a8febbbab355079972fb31ee7c0f33
treedc7909e934473d6b63460c5aa8d0a37ba62a4f79
parent384be2b18a5f9475eab9ca2bdfa95cc1a04ef59c
percpu: fix pcpu_reclaim() locking

pcpu_reclaim() calls pcpu_depopulate_chunk() which makes use of pages
array and bitmap returned by pcpu_get_pages_and_bitmap() and thus
should be called under pcpu_alloc_mutex.  pcpu_reclaim() released the
mutex before calling depopulate leading to double free and other
strange problems caused by the unexpected concurrent usages of pages
array and bitmap.  Fix it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
mm/percpu.c