Commit 195b0c60 authored Apr 15, 2015 by Gioh Kim Committed by Linus Torvalds Apr 15, 2015

mm/compaction: reset compaction scanner positions



When the compaction is activated via /proc/sys/vm/compact_memory it would
better scan the whole zone.  And some platforms, for instance ARM, have
the start_pfn of a zone at zero.  Therefore the first try to compact via
/proc doesn't work.  It needs to reset the compaction scanner position
first.

Signed-off-by: Gioh Kim <gioh.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
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 3b363692

mm/compaction.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -1605,6 +1605,14 @@ static void __compact_pgdat(pg_data_t pgdat, struct compact_control cc)
		INIT_LIST_HEAD(&cc->freepages);
		INIT_LIST_HEAD(&cc->migratepages);

		/*
		* When called via /proc/sys/vm/compact_memory
		* this makes sure we compact the whole zone regardless of
		* cached scanner positions.
		*/
		if (cc->order == -1)
		__reset_isolation_suitable(zone);

		if (cc->order == -1 \|\| !compaction_deferred(zone, cc->order))
		compact_zone(zone, cc);