]> git.karo-electronics.de Git - karo-tx-linux.git/commit
mm: vmscan: do not allow kswapd to scan at maximum priority
authorMel Gorman <mgorman@suse.de>
Thu, 23 May 2013 00:37:17 +0000 (10:37 +1000)
committerStephen Rothwell <sfr@canb.auug.org.au>
Mon, 27 May 2013 06:09:04 +0000 (16:09 +1000)
commit9379b513806d3b9be94eb1727be94d6e5ee5dc23
tree29569e4690ec2f31d603b5690780ffef190c9e7f
parent8bd4258de65d8613375931e099fb580c615c3711
mm: vmscan: do not allow kswapd to scan at maximum priority

Page reclaim at priority 0 will scan the entire LRU as priority 0 is
considered to be a near OOM condition.  Kswapd can reach priority 0 quite
easily if it is encountering a large number of pages it cannot reclaim
such as pages under writeback.  When this happens, kswapd reclaims very
aggressively even though there may be no real risk of allocation failure
or OOM.

This patch prevents kswapd reaching priority 0 and trying to reclaim the
world.  Direct reclaimers will still reach priority 0 in the event of an
OOM situation.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Zlatko Calusic <zcalusic@bitsync.net>
Cc: dormando <dormando@rydia.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/vmscan.c