Commit f3e8eb70 authored Jan 13, 2011 by Johannes Weiner Committed by Linus Torvalds Jan 13, 2011

memcg: fix unit mismatch in memcg oom limit calculation



Adding the number of swap pages to the byte limit of a memory control
group makes no sense.  Convert the pages to bytes before adding them.

The only user of this code is the OOM killer, and the way it is used means
that the error results in a higher OOM badness value.  Since the cgroup
limit is the same for all tasks in the cgroup, the error should have no
practical impact at the moment.

But let's not wait for future or changing users to trip over it.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent dbd4ea78

mm/memcontrol.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -1312,8 +1312,9 @@ u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
		u64 limit;
		u64 memsw;

		limit = res_counter_read_u64(&memcg->res, RES_LIMIT) +
		total_swap_pages;
		limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
		limit += total_swap_pages << PAGE_SHIFT;

		memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
		/*
		* If memsw is finite and limits the amount of swap space available

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