]> 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, 27 Jun 2013 23:51:26 +0000 (09:51 +1000)
committerStephen Rothwell <sfr@canb.auug.org.au>
Fri, 28 Jun 2013 06:37:30 +0000 (16:37 +1000)
commitba1b872b1e930f0ab7722bd271bee1aa40db87b8
tree25162725ef051f5857ab16523d18e241c7dff1c6
parent4afb0311b48276a0ef2c246ae12ef03f79c8b13b
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>
Tested-by: Zlatko Calusic <zcalusic@bitsync.net>
Cc: dormando <dormando@rydia.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/vmscan.c