Commit e33c3b5e authored Nov 12, 2008 by David Rientjes Committed by Linus Torvalds Nov 12, 2008

cpusets: update mems allowed in page allocator



If all allowable memory is unreclaimable, it is possible to loop forever
in the page allocator for ~__GFP_NORETRY allocations.

During this time, it is also possible for a task's cpuset to expand its
set of allowable nodes so that it now includes free memory.  The cached
copy of this set, current->mems_allowed, is stale, however, since there
has not been a subsequent call to cpuset_update_task_memory_state().

The cached copy of the set of allowable nodes is now updated in the page
allocator's slow path so the additional memory is available to
get_page_from_freelist().

[akpm@linux-foundation.org: add comment]
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Paul Menage <menage@google.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent f0f7e0dc

mm/page_alloc.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -1561,6 +1561,10 @@ nofail_alloc:

		/* We now go into synchronous reclaim */
		cpuset_memory_pressure_bump();
		/*
		* The task's cpuset might have expanded its set of allowable nodes
		*/
		cpuset_update_task_memory_state();
		p->flags \|= PF_MEMALLOC;
		reclaim_state.reclaimed_slab = 0;
		p->reclaim_state = &reclaim_state;

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