From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx201.postini.com [74.125.245.201]) by kanga.kvack.org (Postfix) with SMTP id 9B4146B0089 for ; Tue, 14 May 2013 05:28:52 -0400 (EDT) Date: Tue, 14 May 2013 11:28:50 +0200 From: Michal Hocko Subject: Re: [PATCH V2 3/3] memcg: simplify lock of memcg page stat account Message-ID: <20130514092850.GK5198@dhcp22.suse.cz> References: <1368421410-4795-1-git-send-email-handai.szj@taobao.com> <1368421545-4974-1-git-send-email-handai.szj@taobao.com> <20130513131251.GB5246@dhcp22.suse.cz> <20130513133809.GC5246@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Sha Zhengju Cc: KAMEZAWA Hiroyuki , Cgroups , "linux-mm@kvack.org" , Andrew Morton , Hugh Dickins , Greg Thelen , Sha Zhengju On Tue 14-05-13 17:13:07, Sha Zhengju wrote: > On Mon, May 13, 2013 at 9:38 PM, Michal Hocko wrote: > > > > On Mon 13-05-13 15:12:51, Michal Hocko wrote: > > [...] > > > I am sorry but I do not think this is the right approach. IMO we should > > > focus on mem_cgroup_begin_update_page_stat and make it really recursive > > > safe - ideally without any additional overhead (which sounds like a real > > > challenge) > > > > Or maybe we should just not over complicate this and simply consider > > recursivness when it starts being an issue. It is not a problem for > > rmap accounting anymore and dirty pages accounting seems to be safe as > > well and pages under writeback accounting was OK even previously. > > It doesn't make much sense to block dirty pages accounting by a > > non-existing problem. > > > > Yes, the dirty/writeback accounting seems okay now. I sent this patch > out to see if I can do something to simplify the locks but this > approach seems to have its own drawbacks. Since you and Kame are NAK > to this, in the order of importance I'll put the patch aside and > continue the work of dirty page accounting. :) Thanks for your work! > Thanks for the teaching! -- Michal Hocko SUSE Labs -- 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