page allocator: check only once if the zonelist is suitable for the allocation

It is possible with __GFP_THISNODE that no zones are suitable.  This patch
makes sure the check is only made once.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mel Gorman 2009-06-16 15:31:56 -07:00 committed by Linus Torvalds
parent 6484eb3e2a
commit 7f82af9742

View File

@ -1483,9 +1483,8 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
if (should_fail_alloc_page(gfp_mask, order))
return NULL;
restart:
z = zonelist->_zonerefs; /* the list of zones suitable for gfp_mask */
/* the list of zones suitable for gfp_mask */
z = zonelist->_zonerefs;
if (unlikely(!z->zone)) {
/*
* Happens if we have an empty zonelist as a result of
@ -1494,6 +1493,7 @@ restart:
return NULL;
}
restart:
page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET);
if (page)