mm: fix handling of pagesets for downed cpus
authorDimitri Sivanich <sivanich@sgi.com>
Tue, 23 Jun 2009 19:37:04 +0000 (12:37 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 23 Jun 2009 19:50:05 +0000 (12:50 -0700)
commit364df0ebfbbb1330bfc6ca159f4d6020efc15a12
tree80c79bf145d8388ad96a0f7c47a4d25642e403a1
parent01ff53f416757da416413bc32229770a8448b6ef
mm: fix handling of pagesets for downed cpus

After downing/upping a cpu, an attempt to set
/proc/sys/vm/percpu_pagelist_fraction results in an oops in
percpu_pagelist_fraction_sysctl_handler().

If a processor is downed then we need to set the pageset pointer back to
the boot pageset.

Updates of the high water marks should not access pagesets of unpopulated
zones (those pointer go to the boot pagesets which would be no longer
functional if their size would be increased beyond zero).

Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/page_alloc.c