Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753551AbZK0HIP (ORCPT ); Fri, 27 Nov 2009 02:08:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751798AbZK0HIO (ORCPT ); Fri, 27 Nov 2009 02:08:14 -0500 Received: from mail-fx0-f213.google.com ([209.85.220.213]:61173 "EHLO mail-fx0-f213.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751539AbZK0HIO convert rfc822-to-8bit (ORCPT ); Fri, 27 Nov 2009 02:08:14 -0500 MIME-Version: 1.0 In-Reply-To: <661de9470911261908i4bb51e91v649025e6c75bd91b@mail.gmail.com> References: <8524ba285f6dd59cda939c28da523f344cdab3da.1259255307.git.kirill@shutemov.name> <20091127092035.bbf2efdc.nishimura@mxp.nes.nec.co.jp> <20091127114511.bbb43d5a.kamezawa.hiroyu@jp.fujitsu.com> <661de9470911261908i4bb51e91v649025e6c75bd91b@mail.gmail.com> Date: Fri, 27 Nov 2009 09:08:19 +0200 Message-ID: Subject: Re: [PATCH RFC v0 2/3] res_counter: implement thresholds From: "Kirill A. Shutemov" To: Balbir Singh , KAMEZAWA Hiroyuki , Daisuke Nishimura Cc: containers@lists.linux-foundation.org, linux-mm@kvack.org, Paul Menage , Li Zefan , Andrew Morton , Pavel Emelyanov , linux-kernel@vger.kernel.org, Dan Malek , Vladislav Buzov Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2123 Lines: 59 On Fri, Nov 27, 2009 at 5:08 AM, Balbir Singh wrote: > On Fri, Nov 27, 2009 at 8:15 AM, KAMEZAWA Hiroyuki > wrote: >> On Fri, 27 Nov 2009 09:20:35 +0900 >> Daisuke Nishimura wrote: >> >>> Hi. >>> > >>> > @@ -73,6 +76,7 @@ void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val) >>> >             val = counter->usage; >>> > >>> >     counter->usage -= val; >>> > +   res_counter_threshold_notify_locked(counter); >>> >  } >>> > >>> hmm.. this adds new checks to hot-path of process life cycle. >>> >>> Do you have any number on performance impact of these patches(w/o setting any threshold)? No, I don't. I did only functional testing on this stage. >>> IMHO, it might be small enough to be ignored because KAMEZAWA-san's coalesce charge/uncharge >>> patches have decreased charge/uncharge for res_counter itself, but I want to know just to make sure. >>> >> Another concern is to support root cgroup, you need another notifier hook in >> memcg because root cgroup doesn't use res_counter now. >> >> Can't this be implemented in a way like softlimit check ? I'll investigate it. >> Filter by the number of event will be good for notifier behavior, for avoiding >> too much wake up, too. Good idea, thanks. > I guess the semantics would vary then, they would become activity > semantics. I think we should avoid threshold notification for root, > since we have no limits in root anymore. Threshold notifications for root cgroup is really needed on embedded systems to avid OOM-killer. > > BTW, Kirill, I've been meaning to write this layer on top of > cgroupstats, is there anything that prevents us from using that today? I'll investigate it. > CC'ing Dan Malek and Vladslav Buzov who worked on similar patches > earlier. > > Balbir Singh. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/