Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758206Ab1FBAgH (ORCPT ); Wed, 1 Jun 2011 20:36:07 -0400 Received: from smtp-out.google.com ([216.239.44.51]:60890 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753446Ab1FBAgF convert rfc822-to-8bit (ORCPT ); Wed, 1 Jun 2011 20:36:05 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type:content-transfer-encoding; b=o7MjlcgxyIauGaSpoIg58Zl6qiUeVPQV8q4jnC8GrAc9DaUgKPGNwXLUTpmpZlPZzt wInwz7lqnAekgxyBBiTg== MIME-Version: 1.0 In-Reply-To: References: <1306909519-7286-1-git-send-email-hannes@cmpxchg.org> From: Greg Thelen Date: Wed, 1 Jun 2011 17:35:37 -0700 Message-ID: Subject: Re: [patch 0/8] mm: memcg naturalization -rc2 To: Hiroyuki Kamezawa Cc: Johannes Weiner , KAMEZAWA Hiroyuki , Daisuke Nishimura , Balbir Singh , Ying Han , Michal Hocko , Andrew Morton , Rik van Riel , Minchan Kim , KOSAKI Motohiro , Mel Gorman , Michel Lespinasse , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4389 Lines: 104 On Wed, Jun 1, 2011 at 4:52 PM, Hiroyuki Kamezawa wrote: > 2011/6/1 Johannes Weiner : >> Hi, >> >> this is the second version of the memcg naturalization series. ?The >> notable changes since the first submission are: >> >> ? ?o the hierarchy walk is now intermittent and will abort and >> ? ? ?remember the last scanned child after sc->nr_to_reclaim pages >> ? ? ?have been reclaimed during the walk in one zone (Rik) >> >> ? ?o the global lru lists are never scanned when memcg is enabled >> ? ? ?after #2 'memcg-aware global reclaim', which makes this patch >> ? ? ?self-sufficient and complete without requiring the per-memcg lru >> ? ? ?lists to be exclusive (Michal) >> >> ? ?o renamed sc->memcg and sc->current_memcg to sc->target_mem_cgroup >> ? ? ?and sc->mem_cgroup and fixed their documentation, I hope this is >> ? ? ?better understandable now (Rik) >> >> ? ?o the reclaim statistic counters have been renamed. ?there is no >> ? ? ?more distinction between 'pgfree' and 'pgsteal', it is now >> ? ? ?'pgreclaim' in both cases; 'kswapd' has been replaced by >> ? ? ?'background' >> >> ? ?o fixed a nasty crash in the hierarchical soft limit check that >> ? ? ?happened during global reclaim in memcgs that are hierarchical >> ? ? ?but have no hierarchical parents themselves >> >> ? ?o properly implemented the memcg-aware unevictable page rescue >> ? ? ?scanner, there were several blatant bugs in there >> >> ? ?o documentation on new public interfaces >> >> Thanks for your input on the first version. >> >> I ran microbenchmarks (sparse file catting, essentially) to stress >> reclaim and LRU operations. ?There is no measurable overhead for >> !CONFIG_MEMCG, memcg disabled during boot, memcg enabled but no >> configured groups, and hard limit reclaim. >> >> I also ran single-threaded kernbenchs in four unlimited memcgs in >> parallel, contained in a hard-limited hierarchical parent that put >> constant pressure on the workload. ?There is no measurable difference >> in runtime, the pgpgin/pgpgout counters, and fairness among memcgs in >> this test compared to an unpatched kernel. ?Needs more evaluation, >> especially with a higher number of memcgs. >> >> The soft limit changes are also proven to work in so far that it is >> possible to prioritize between children in a hierarchy under pressure >> and that runtime differences corresponded directly to the soft limit >> settings in the previously described kernbench setup with staggered >> soft limits on the groups, but this needs quantification. >> >> Based on v2.6.39. >> > > Hmm, I welcome and will review this patches but.....some points I want to say. > > 1. No more conflict with Ying's work ? > ? ?Could you explain what she has and what you don't in this v2 ? > ? ?If Ying's one has something good to be merged to your set, please > include it. > > 2. it's required to see performance score in commit log. > > 3. I think dirty_ratio as 1st big patch to be merged. (But...hmm..Greg ? > ? ?My patches for asynchronous reclaim is not very important. I can rework it. I am testing the next version (v8) of the memcg dirty ratio patches. I expect to have it posted for review later this week. > 4. This work can be splitted into some small works. > ? ? a) fix for current code and clean ups > ? ? a') statistics > ? ? b) soft limit rework > ? ? c) change global reclaim > > ?I like (a)->(b)->(c) order. and while (b) you can merge your work > with Ying's one. > ?And for a') , I'd like to add a new file memory.reclaim_stat as I've > already shown. > ?and allow resetting. > > ?Hmm, how about splitting patch 2/8 into small patches and see what happens in > ?3.2 or 3.3 ? While that, we can make softlimit works better. > ?(and once we do 2/8, our direction will be fixed to the direction to > remove global LRU.) > > 5. please write documentation to explain what new LRU do. > > BTW, after this work, lists of ROOT cgroup comes again. I may need to check > codes which see memcg is ROOT or not. Because we removed many atomic > ops in memcg, I wonder ROOT cgroup can be accounted again.. > > Thanks, > -Kame > -- 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/