From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx113.postini.com [74.125.245.113]) by kanga.kvack.org (Postfix) with SMTP id AF9056B0072 for ; Tue, 13 Nov 2012 19:13:46 -0500 (EST) Received: from m3.gw.fujitsu.co.jp (unknown [10.0.50.73]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 4A8953EE0C1 for ; Wed, 14 Nov 2012 09:13:45 +0900 (JST) Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 282C945DEBC for ; Wed, 14 Nov 2012 09:13:45 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 09B3645DEB5 for ; Wed, 14 Nov 2012 09:13:45 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id C67F3E08003 for ; Wed, 14 Nov 2012 09:13:44 +0900 (JST) Received: from m1001.s.css.fujitsu.com (m1001.s.css.fujitsu.com [10.240.81.139]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 75DED1DB803F for ; Wed, 14 Nov 2012 09:13:44 +0900 (JST) Message-ID: <50A2E229.3050809@jp.fujitsu.com> Date: Wed, 14 Nov 2012 09:13:29 +0900 From: Kamezawa Hiroyuki MIME-Version: 1.0 Subject: Re: [RFC] rework mem_cgroup iterator References: <1352820639-13521-1-git-send-email-mhocko@suse.cz> In-Reply-To: <1352820639-13521-1-git-send-email-mhocko@suse.cz> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Johannes Weiner , Ying Han , Tejun Heo , Glauber Costa (2012/11/14 0:30), Michal Hocko wrote: > Hi all, > this patch set tries to make mem_cgroup_iter saner in the way how it > walks hierarchies. css->id based traversal is far from being ideal as it > is not deterministic because it depends on the creation ordering. > > Diffstat looks promising but it is fair the say that the biggest cleanup is > just css_get_next removal. The memcg code has grown a bit but I think it is > worth the resulting outcome (the sanity ;)). > > The first patch fixes a potential misbehaving which I haven't seen but the > fix is needed for the later patches anyway. We could take it alone as well > but I do not have any bug report to base the fix on. > > The second patch replaces css_get_next by cgroup iterators which are > scheduled for 3.8 in Tejun's tree and I depend on the following two patches: > fe1e904c cgroup: implement generic child / descendant walk macros > 7e187c6c cgroup: use rculist ops for cgroup->children > > The third patch is an attempt for simplification of the mem_cgroup_iter. It > basically removes all css usages to make the code easier. The next patch > removes the big while(!memcg) loop around the iterating logic. It could have > been folded into #3 but I rather have the rework separate from the code > moving noise. > > The last patch just removes css_get_next as there is no user for it any > longer. > > I am also thinking that leaf-to-root iteration makes more sense but this > patch is not included in the series yet because I have to think some > more about the justification. > > So far I didn't get to testing but I am posting this early if everybody is > OK with this change. > > Any thoughts? > I'm O.K. Maybe I have some points I'm not understanding...I'll make a reply to patches. 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/ . Don't email: email@kvack.org