From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx122.postini.com [74.125.245.122]) by kanga.kvack.org (Postfix) with SMTP id 557C96B00A7 for ; Mon, 15 Oct 2012 10:25:35 -0400 (EDT) Received: by mail-oa0-f41.google.com with SMTP id k14so6175264oag.14 for ; Mon, 15 Oct 2012 07:25:34 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20121015094907.GE29069@dhcp22.suse.cz> References: <20121010141142.GG23011@dhcp22.suse.cz> <507BD33C.4030209@jp.fujitsu.com> <20121015094907.GE29069@dhcp22.suse.cz> From: KOSAKI Motohiro Date: Mon, 15 Oct 2012 10:25:14 -0400 Message-ID: Subject: Re: [RFC PATCH] memcg: oom: fix totalpages calculation for swappiness==0 Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Kamezawa Hiroyuki , linux-mm@kvack.org, David Rientjes , Johannes Weiner , LKML > diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt > index 078701f..308fd77 100644 > --- a/Documentation/sysctl/vm.txt > +++ b/Documentation/sysctl/vm.txt > @@ -640,6 +640,9 @@ swappiness > This control is used to define how aggressive the kernel will swap > memory pages. Higher values will increase agressiveness, lower values > decrease the amount of swap. > +The value can be used from the [0, 100] range, where 0 means no swapping > +at all (even if there is a swap storage enabled) while 100 means that > +anonymous pages are reclaimed in the same rate as file pages. I think this only correct when memcg. Even if swappiness==0, global reclaim swap out anon pages before oom. see below. get_scan_count() (snip) if (global_reclaim(sc)) { free = zone_page_state(zone, NR_FREE_PAGES); /* If we have very few page cache pages, force-scan anon pages. */ if (unlikely(file + free <= high_wmark_pages(zone))) { fraction[0] = 1; fraction[1] = 0; denominator = 1; goto out; } } -- 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