tree e2e6fd3df079f85c43c7e164569a8c962f91e537
parent a01e035ebb552223c03f2d9138ffc73f2d4d3965
author KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> 1209455901 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1209481558 -0700

mm: fix usemap initialization

usemap must be initialized only when pfn is within zone.  If not, it corrupts
memory.

And this patch also reduces the number of calls to set_pageblock_migratetype()
from
	(pfn & (pageblock_nr_pages -1)
to
	!(pfn & (pageblock_nr_pages-1)
it should be called once per pageblock.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Shi Weihua <shiwh@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>