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 ESMTP id 02D9E9000BD for ; Mon, 3 Oct 2011 06:05:12 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp (unknown [10.0.50.71]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id B16C63EE0BC for ; Mon, 3 Oct 2011 19:05:08 +0900 (JST) Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 96BE345DE5F for ; Mon, 3 Oct 2011 19:05:08 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 747D845DE5D for ; Mon, 3 Oct 2011 19:05:08 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 629521DB804C for ; Mon, 3 Oct 2011 19:05:08 +0900 (JST) Received: from m106.s.css.fujitsu.com (m106.s.css.fujitsu.com [10.240.81.146]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 2D4731DB803A for ; Mon, 3 Oct 2011 19:05:08 +0900 (JST) Date: Mon, 3 Oct 2011 19:04:11 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [patch 00/10] memcg naturalization -rc4 Message-Id: <20111003190411.2c8c6b29.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20110930093231.GE30857@redhat.com> References: <1317330064-28893-1-git-send-email-jweiner@redhat.com> <20110930170510.4695b8f0.kamezawa.hiroyu@jp.fujitsu.com> <20110930093231.GE30857@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Andrew Morton , Michal Hocko , "Kirill A. Shutemov" , Daisuke Nishimura , Balbir Singh , Ying Han , Greg Thelen , Michel Lespinasse , Rik van Riel , Minchan Kim , Christoph Hellwig , Hugh Dickins , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Fri, 30 Sep 2011 11:32:31 +0200 Johannes Weiner wrote: > On Fri, Sep 30, 2011 at 05:05:10PM +0900, KAMEZAWA Hiroyuki wrote: > > On Thu, 29 Sep 2011 23:00:54 +0200 > > Thank you for your work. Now, I'm ok this series to be tested in -mm. > > Ack. to all. > > Thanks! > > > Do you have any plan, concerns ? > > I would really like to get them into 3.2. While it's quite intrusive, > I stress-tested various scenarios for quite some time - tests that > revealed more bugs in the existing memcg code than in my changes - so > I don't expect too big surprises. AFAICS, Google uses these patches > internally already and their bug reports early on also helped iron out > the most obvious problems. > > What I am concerned about is the scalability on setups with thousands > of tiny memcgs that go into global reclaim, as this would try to scan > pages from all existing memcgs. There is a mitigating factor in that > concurrent reclaimers divide the memcgs to scan among themselves (the > shared mem_cgroup_reclaim_iter), and with hundreds or thousands of > memcgs, I expect several threads to go into reclaim upon global memory > pressure at the same time in the common case. I don't have the means > to test this and I also don't know if such setups exist or are within > the realm of sanity that we would like to support, anyway. As far as I hear, some users use hundreds of memcg in a host. > If this > shows up, I think the fix would be as easy as bailing out early from > the hierarchy walk, but I would like to cross that bridge when we come > to it. > > Other than that, I see no reason to hold it off. Traditional reclaim > without memcgs except root_mem_cgroup - what most people care about - > is mostly unaffected. There is a real interest in the series, and > maintaining it out-of-tree is a major pain and quite error prone. > > What do you think? > I think this should be merged/tested as soon as possible because this patch must be a base for memcg patches which are now being developped. Thanks, -Kame -- 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