From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id 9D6616B012E for ; Fri, 12 Mar 2010 05:01:37 -0500 (EST) Date: Fri, 12 Mar 2010 11:01:29 +0100 From: Andrea Righi Subject: Re: [PATCH -mmotm 0/5] memcg: per cgroup dirty limit (v6) Message-ID: <20100312100129.GB4438@linux> References: <1268175636-4673-1-git-send-email-arighi@develer.com> <20100311093913.07c9ca8a.kamezawa.hiroyu@jp.fujitsu.com> <20100311101726.f58d24e9.kamezawa.hiroyu@jp.fujitsu.com> <1268298865.5279.997.camel@twins> <20100311182500.0f3ba994.kamezawa.hiroyu@jp.fujitsu.com> <20100311150307.GC29246@redhat.com> <20100311232708.GE2427@linux> <20100312085244.98e48991.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100312085244.98e48991.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: Vivek Goyal , Peter Zijlstra , Balbir Singh , Daisuke Nishimura , Trond Myklebust , Suleiman Souhlal , Greg Thelen , "Kirill A. Shutemov" , Andrew Morton , containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Fri, Mar 12, 2010 at 08:52:44AM +0900, KAMEZAWA Hiroyuki wrote: > On Fri, 12 Mar 2010 00:27:09 +0100 > Andrea Righi wrote: > > > On Thu, Mar 11, 2010 at 10:03:07AM -0500, Vivek Goyal wrote: > > > > I am still setting up the system to test whether we see any speedup in > > > writeout of large files with-in a memory cgroup with small memory limits. > > > I am assuming that we are expecting a speedup because we will start > > > writeouts early and background writeouts probably are faster than direct > > > reclaim? > > > > mmh... speedup? I think with a large file write + reduced dirty limits > > you'll get a more uniform write-out (more frequent small writes), > > respect to few and less frequent large writes. The system will be more > > reactive, but I don't think you'll be able to see a speedup in the large > > write itself. > > > Ah, sorry. I misunderstood something. But it's depends on dirty_ratio param. > If > background_dirty_ratio = 5 > dirty_ratio = 100 > under 100M cgroup, I think background write-out will be a help. Right, in this case background flusher threads will help a lot to write-out the cgroup dirty memory and it'll get better performance. -Andrea -- 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