Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752505Ab1EQILX (ORCPT ); Tue, 17 May 2011 04:11:23 -0400 Received: from zene.cmpxchg.org ([85.214.230.12]:54797 "EHLO zene.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751255Ab1EQILR (ORCPT ); Tue, 17 May 2011 04:11:17 -0400 Date: Tue, 17 May 2011 10:11:00 +0200 From: Johannes Weiner To: Ying Han Cc: KAMEZAWA Hiroyuki , Daisuke Nishimura , Balbir Singh , Michal Hocko , Andrew Morton , Rik van Riel , Minchan Kim , KOSAKI Motohiro , Mel Gorman , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [rfc patch 0/6] mm: memcg naturalization Message-ID: <20110517081100.GZ16531@cmpxchg.org> References: <1305212038-15445-1-git-send-email-hannes@cmpxchg.org> <20110513072043.GE18610@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2435 Lines: 61 On Mon, May 16, 2011 at 05:53:04PM -0700, Ying Han wrote: > On Fri, May 13, 2011 at 12:20 AM, Johannes Weiner wrote: > > > On Thu, May 12, 2011 at 11:53:37AM -0700, Ying Han wrote: > > > On Thu, May 12, 2011 at 7:53 AM, Johannes Weiner > > wrote: > > > > > > > Hi! > > > > > > > > Here is a patch series that is a result of the memcg discussions on > > > > LSF (memcg-aware global reclaim, global lru removal, struct > > > > page_cgroup reduction, soft limit implementation) and the recent > > > > feature discussions on linux-mm. > > > > > > > > The long-term idea is to have memcgs no longer bolted to the side of > > > > the mm code, but integrate it as much as possible such that there is a > > > > native understanding of containers, and that the traditional !memcg > > > > setup is just a singular group. This series is an approach in that > > > > direction. > > > > This sounds like a good long term plan. Now I would wonder should we take it > step by step by doing: > > 1. improving the existing soft_limit reclaim from RB-tree based to link-list > based, also in a round_robin fashion. > We can keep the existing APIs but only changing the underlying > implementation of mem_cgroup_soft_limit_reclaim() > > 2. remove the global lru list after the first one being proved to be > efficient. > > 3. then have better integration of memcg reclaim to the mm code. I chose to go the other because it did not seem more complex to me and fixed many things we had planned anyway. Deeper integration, better soft limit implementation (including better pressure distribution, enforcement also from direct reclaim, not just kswapd), global lru removal etc. That ground work was a bit unwieldy and I think quite some confusion ensued, but I am currently reorganizing, cleaning up, and documenting. I expect the next version to be much easier to understand. The three steps are still this: 1. make traditional reclaim memcg-aware. 2. improve soft limit based on 1. 3. remove global lru based on 1. But 1. already effectively disables the global LRU for memcg-enabled kernels, so 3. can be deferred until we are comfortable with 1. Hannes -- 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/