Re: [BUGFIX][PATCH] memcg: fix wrong decision of noswap with softlimit.
From: Michal Hocko <hidden>
Date: 2011-06-12 11:22:37
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On Thu 09-06-11 09:54:45, KAMEZAWA Hiroyuki wrote:
I wonder this should go stable... == From e2565de1c764057b75b4d9a1674d163b6c873cdd Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki <redacted> Date: Thu, 9 Jun 2011 09:54:32 +0900 Subject: [PATCH 2/2] Fix softlimit wrong check of noswap Now, hierarchical reclaim doesn't make swap if memory's limit is equal to mem+swap limit. Because if reclaim does swap-out, it still hits mem+swap limit and there will be no progress. WHEN HITTING HARD LIMIT. When it comes to softlimit, it works for kswapd. noswap is nonsense. Signed-off-by: KAMEZAWA Hiroyuki <redacted>
Maybe the changelog should be more clear. What about something like: " Hierarchical reclaim doesn't swap out if memsw and resource limits are same (memsw_is_minimum == true) because we would hit mem+swap limit anyway (during hard limit reclaim). If it comes to the solft limit we shouldn't consider memsw_is_minimum at all because it doesn't make much sense. Either the soft limit is bellow the hard limit and then we cannot hit mem+swap limit or the direct reclaim takes a precedence. " Reviewed-by: Michal Hocko <redacted>
quoted hunk ↗ jump to hunk
--- mm/memcontrol.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 3baddcb..06825be 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c@@ -1663,7 +1663,7 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem, excess = res_counter_soft_limit_excess(&root_mem->res) >> PAGE_SHIFT; /* If memsw_is_minimum==1, swap-out is of-no-use. */ - if (root_mem->memsw_is_minimum) + if (!check_soft && root_mem->memsw_is_minimum) noswap = true; while (1) {-- 1.7.4.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
-- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>