Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759445Ab1FBHus (ORCPT ); Thu, 2 Jun 2011 03:50:48 -0400 Received: from zene.cmpxchg.org ([85.214.230.12]:55827 "EHLO zene.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751404Ab1FBHuq (ORCPT ); Thu, 2 Jun 2011 03:50:46 -0400 Date: Thu, 2 Jun 2011 09:50:28 +0200 From: Johannes Weiner To: Ying Han Cc: Hiroyuki Kamezawa , KAMEZAWA Hiroyuki , Daisuke Nishimura , Balbir Singh , Michal Hocko , Andrew Morton , Rik van Riel , Minchan Kim , KOSAKI Motohiro , Mel Gorman , Greg Thelen , Michel Lespinasse , "linux-mm@kvack.org" , linux-kernel Subject: Re: [patch 0/8] mm: memcg naturalization -rc2 Message-ID: <20110602075028.GB20630@cmpxchg.org> References: <1306909519-7286-1-git-send-email-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4493 Lines: 106 On Wed, Jun 01, 2011 at 09:05:18PM -0700, Ying Han wrote: > 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 ?'pgreclaim' in both cases; 'kswapd' has been replaced by 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. > > My patch I sent out last time was doing rework of soft_limit reclaim. > It convert the RB-tree based to > a linked list round-robin fashion of all memcgs across their soft > limit per-zone. > > I will apply this patch and try to test it. After that i will get > better idea whether or not it is being covered here. Thanks!! > > 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 > > My last patchset starts with a patch reverting the RB-tree > implementation of the soft_limit > reclaim, and then the new round-robin implementation comes on the > following patches. > > I like the ordering here, and that is consistent w/ the plan we > discussed earlier in LSF. Changing > the global reclaim would be the last step when the changes before that > have been well understood > and tested. > > Sorry If that is how it is done here. I will read through the patchset. It's not. The way I implemented soft limits depends on global reclaim performing hierarchical reclaim. I don't see how I can reverse the order with this dependency. -- 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/