From: Vladimir Davydov Date: Wed, 10 Dec 2014 23:44:16 +0000 (-0800) Subject: memcg: remove mem_cgroup_reclaimable check from soft reclaim X-Git-Tag: omap-for-v3.20/drop-legacy-3517~139^2~124 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4ef461e8f4dd13a2e64c6c8f00c420d62294e2d4;p=pandora-kernel.git memcg: remove mem_cgroup_reclaimable check from soft reclaim mem_cgroup_reclaimable() checks whether a cgroup has reclaimable pages on *any* NUMA node. However, the only place where it's called is mem_cgroup_soft_reclaim(), which tries to reclaim memory from a *specific* zone. So the way it is used is incorrect - it will return true even if the cgroup doesn't have pages on the zone we're scanning. I think we can get rid of this check completely, because mem_cgroup_shrink_node_zone(), which is called by mem_cgroup_soft_reclaim() if mem_cgroup_reclaimable() returns true, is equivalent to shrink_lruvec(), which exits almost immediately if the lruvec passed to it is empty. So there's no need to optimize anything here. Besides, we don't have such a check in the general scan path (shrink_zone) either. Signed-off-by: Vladimir Davydov Acked-by: Michal Hocko Acked-by: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed