From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 2B9C86B007E for ; Wed, 8 Jun 2011 11:04:58 -0400 (EDT) Date: Wed, 8 Jun 2011 17:04:47 +0200 From: Michal Hocko Subject: Re: [patch 8/8] mm: make per-memcg lru lists exclusive Message-ID: <20110608145002.GB9936@tiehlicka.suse.cz> References: <1306909519-7286-1-git-send-email-hannes@cmpxchg.org> <1306909519-7286-9-git-send-email-hannes@cmpxchg.org> <20110602142408.GB28684@cmpxchg.org> <20110602175702.GI28684@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110602175702.GI28684@cmpxchg.org> Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Hiroyuki Kamezawa , KAMEZAWA Hiroyuki , Daisuke Nishimura , Balbir Singh , Ying Han , Andrew Morton , Rik van Riel , Minchan Kim , KOSAKI Motohiro , Mel Gorman , Greg Thelen , Michel Lespinasse , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Thu 02-06-11 19:57:02, Johannes Weiner wrote: > On Fri, Jun 03, 2011 at 12:54:39AM +0900, Hiroyuki Kamezawa wrote: > > 2011/6/2 Johannes Weiner : > > > On Thu, Jun 02, 2011 at 10:16:59PM +0900, Hiroyuki Kamezawa wrote: [...] > > > But it may put a page onto wrong memcgs if we do link a page to > > another page's page->lru > > because 2 pages may be in different cgroup each other. > > Yes, I noticed that. If it splits a huge page, it does not just add > the tailpages to the lru head, but it links them next to the head > page. > > But I don't see how those pages could ever be in different memcgs? > pages with page->mapping pointing to the same anon_vma are always in > the same memcg, AFAIU. Process can be moved to other memcg and without move_charge_at_immigrate all previously faulted pages stay in the original group while all new (not faulted yet) get into the new group while mapping doesn't change. I guess this might happen with thp tailpages as well. But I do not think this is a problem. The original group already got charged for the huge page so we can keep all tail pages in it. -- 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: email@kvack.org