From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx142.postini.com [74.125.245.142]) by kanga.kvack.org (Postfix) with SMTP id 5B0026B0062 for ; Sun, 17 Jun 2012 22:56:27 -0400 (EDT) Received: from m2.gw.fujitsu.co.jp (unknown [10.0.50.72]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 486953EE0C0 for ; Mon, 18 Jun 2012 11:56:25 +0900 (JST) Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 2E51D45DE59 for ; Mon, 18 Jun 2012 11:56:25 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 0CDA045DE52 for ; Mon, 18 Jun 2012 11:56:25 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id EA4B01DB802C for ; Mon, 18 Jun 2012 11:56:24 +0900 (JST) Received: from m1000.s.css.fujitsu.com (m1000.s.css.fujitsu.com [10.240.81.136]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 9C26B1DB803E for ; Mon, 18 Jun 2012 11:56:24 +0900 (JST) Message-ID: <4FDE9857.7000801@jp.fujitsu.com> Date: Mon, 18 Jun 2012 11:54:15 +0900 From: Kamezawa Hiroyuki MIME-Version: 1.0 Subject: Re: [PATCH 3/5] mm: memcg detect no memcgs above softlimit under zone reclaim. References: <1339007031-10527-1-git-send-email-yinghan@google.com> In-Reply-To: <1339007031-10527-1-git-send-email-yinghan@google.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Ying Han Cc: Michal Hocko , Johannes Weiner , Rik van Riel , Hillf Danton , Hugh Dickins , Greg Thelen , Dan Magenheimer , Andrew Morton , linux-mm@kvack.org (2012/06/07 3:23), Ying Han wrote: > In memcg kernel, cgroup under its softlimit is not targeted under global > reclaim. It could be possible that all memcgs are under their softlimit for > a particular zone. If that is the case, the current implementation will > burn extra cpu cycles without making forward progress. > > The idea is from LSF discussion where we detect it after the first round of > scanning and restart the reclaim by not looking at softlimit at all. This > allows us to make forward progress on shrink_zone(). > > Signed-off-by: Ying Han Hm, how about adding sc->ignore_softlimit and preserve the result among priority loops ? Is it better to check 'ignore_softlimit' at every priority updates ? Thanks, -Kame > --- > mm/vmscan.c | 18 ++++++++++++++++-- > 1 files changed, 16 insertions(+), 2 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 0560783..5d036f5 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2142,6 +2142,10 @@ static void shrink_zone(int priority, struct zone *zone, > .priority = priority, > }; > struct mem_cgroup *memcg; > + bool over_softlimit, ignore_softlimit = false; > + > +restart: > + over_softlimit = false; > > memcg = mem_cgroup_iter(root, NULL,&reclaim); > do { > @@ -2163,9 +2167,14 @@ static void shrink_zone(int priority, struct zone *zone, > * we have to reclaim under softlimit instead of burning more > * cpu cycles. > */ > - if (!global_reclaim(sc) || priority< DEF_PRIORITY - 2 || > - should_reclaim_mem_cgroup(memcg)) > + if (ignore_softlimit || !global_reclaim(sc) || > + priority< DEF_PRIORITY - 2 || > + should_reclaim_mem_cgroup(memcg)) { > shrink_mem_cgroup_zone(priority,&mz, sc); > + > + over_softlimit = true; > + } > + > /* > * Limit reclaim has historically picked one memcg and > * scanned it with decreasing priority levels until > @@ -2182,6 +2191,11 @@ static void shrink_zone(int priority, struct zone *zone, > } > memcg = mem_cgroup_iter(root, memcg,&reclaim); > } while (memcg); > + > + if (!over_softlimit) { > + ignore_softlimit = true; > + goto restart; > + } > } > > /* Returns true if compaction should go ahead for a high-order request */ -- 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/ . Don't email: email@kvack.org