Michal Hocko 9a5a8f19b4 memcg: oom: fix totalpages calculation for memory.swappiness==0 ... oom_badness() takes a totalpages argument which says how many pages are available and it uses it as a base for the score calculation. The value is calculated by mem_cgroup_get_limit which considers both limit and total_swap_pages (resp. memsw portion of it). This is usually correct but since fe35004fbf ("mm: avoid swapping out with swappiness==0") we do not swap when swappiness is 0 which means that we cannot really use up all the totalpages pages. This in turn confuses oom score calculation if the memcg limit is much smaller than the available swap because the used memory (capped by the limit) is negligible comparing to totalpages so the resulting score is too small if adj!=0 (typically task with CAP_SYS_ADMIN or non zero oom_score_adj). A wrong process might be selected as result. The problem can be worked around by checking mem_cgroup_swappiness==0 and not considering swap at all in such a case. Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2012-11-16 14:33:04 -08:00
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00-INDEX
blkio-controller.txt	Documentation: Fix multiple typo in Documentation	2012-03-07 16:08:24 +01:00
cgroup_event_listener.c	tree-wide: fix comment/printk typos	2010-11-01 15:38:34 -04:00
cgroups.txt	cgroup: trivial fixes for Documentation/cgroups/cgroups.txt	2012-09-13 11:10:54 -07:00
cpuacct.txt	Documentation: fix echo command in cgroups/cpuacct.txt	2011-07-23 10:58:08 -07:00
cpusets.txt	documentation: remove references to cpu_*_map.	2012-03-29 15:38:31 +10:30
devices.txt	Documentation: update cgroupfs mount point	2011-06-15 21:52:50 -07:00
freezer-subsystem.txt	Documentation: Fix typo in freezer-subsystem.txt	2011-11-07 23:02:25 +01:00
hugetlb.txt	hugetlb/cgroup: add HugeTLB controller documentation	2012-07-31 18:42:41 -07:00
memcg_test.txt	tree-wide: fix comment/printk typos	2010-11-01 15:38:34 -04:00
memory.txt	memcg: oom: fix totalpages calculation for memory.swappiness==0	2012-11-16 14:33:04 -08:00
net_prio.txt	net: add documentation for net_prio cgroups (v4)	2011-11-22 15:22:23 -05:00
resource_counter.txt	rescounters: add res_counter_uncharge_until()	2012-05-29 16:22:27 -07:00