From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id 67160900001 for ; Thu, 28 Apr 2011 23:29:03 -0400 (EDT) Received: from kpbe14.cbf.corp.google.com (kpbe14.cbf.corp.google.com [172.25.105.78]) by smtp-out.google.com with ESMTP id p3T3T1mX003792 for ; Thu, 28 Apr 2011 20:29:01 -0700 Received: from qwc23 (qwc23.prod.google.com [10.241.193.151]) by kpbe14.cbf.corp.google.com with ESMTP id p3T3StDQ018524 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NOT) for ; Thu, 28 Apr 2011 20:28:59 -0700 Received: by qwc23 with SMTP id 23so2333905qwc.17 for ; Thu, 28 Apr 2011 20:28:55 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <1304030226-19332-1-git-send-email-yinghan@google.com> <1304030226-19332-3-git-send-email-yinghan@google.com> Date: Thu, 28 Apr 2011 20:28:54 -0700 Message-ID: Subject: Re: [PATCH 2/2] Add stats to monitor soft_limit reclaim From: Ying Han Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Hiroyuki Kamezawa Cc: KOSAKI Motohiro , Minchan Kim , Daisuke Nishimura , Balbir Singh , Tejun Heo , Pavel Emelyanov , KAMEZAWA Hiroyuki , Andrew Morton , Li Zefan , Mel Gorman , Christoph Lameter , Johannes Weiner , Rik van Riel , Hugh Dickins , Michal Hocko , Dave Hansen , Zhu Yanhai , linux-mm@kvack.org On Thu, Apr 28, 2011 at 4:51 PM, Hiroyuki Kamezawa wrote: > 2011/4/29 Ying Han : >> On Thu, Apr 28, 2011 at 3:37 PM, Ying Han wrote: >>> This patch extend the soft_limit reclaim stats to both global backgroun= d >>> reclaim and global direct reclaim. >>> >>> We have a thread discussing the naming of some of the stats. Both >>> KAMEZAWA and Johannes posted the proposals. The following stats are bas= ed >>> on what i had before that thread. I will make the corresponding change = on >>> the next post when we make decision. >>> >>> $cat /dev/cgroup/memory/A/memory.stat >>> kswapd_soft_steal 1053626 >>> kswapd_soft_scan 1053693 >>> direct_soft_steal 1481810 >>> direct_soft_scan 1481996 >>> >>> Signed-off-by: Ying Han >>> --- >>> =A0Documentation/cgroups/memory.txt | =A0 10 ++++- >>> =A0mm/memcontrol.c =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0| =A0 68 ++++++++= ++++++++++++++++++++---------- >>> =A02 files changed, 58 insertions(+), 20 deletions(-) >>> >>> diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/m= emory.txt >>> index 0c40dab..fedc107 100644 >>> --- a/Documentation/cgroups/memory.txt >>> +++ b/Documentation/cgroups/memory.txt >>> @@ -387,8 +387,14 @@ pgpgout =A0 =A0 =A0 =A0 =A0 =A0- # of pages paged = out (equivalent to # of uncharging events). >>> =A0swap =A0 =A0 =A0 =A0 =A0 - # of bytes of swap usage >>> =A0pgfault =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0- # of page faults. >>> =A0pgmajfault =A0 =A0 - # of major page faults. >>> -soft_steal =A0 =A0 - # of pages reclaimed from global hierarchical rec= laim >>> -soft_scan =A0 =A0 =A0- # of pages scanned from global hierarchical rec= laim >>> +soft_kswapd_steal- # of pages reclaimed in global hierarchical reclaim= from >>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 background reclaim >>> +soft_kswapd_scan - # of pages scanned in global hierarchical reclaim f= rom >>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 background reclaim >>> +soft_direct_steal- # of pages reclaimed in global hierarchical reclaim= from >>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 direct reclaim >>> +soft_direct_scan- # of pages scanned in global hierarchical reclaim fr= om >>> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 direct reclaim > > Thank you for CC. > > I don't have strong opinion but once we add interfaces to mainline, > it's hard to rename them. So, it's better to make a list of what name > we'll need in future. > > Now, your naming has a format as [Reason]-[Who reclaim]-[What count?] > soft_kswapd_steal > soft_kswapd_scan > soft_direct_steal > soft_direct_scan > > Ok, we can make a name for wmark and limit reclaim as > > limit_direct_steal/scan > wmark_bg_steal/scan > > Then, assume we finally do round-robin scan of memcg regardless of softli= mit by > removing global LRU, what name do we have ? Hmm, > > kernel_kswapd_scan/steal > kernel_direct_scan/steal > > ? Johannes has the proposal to separate out reclaims on the memcg internally and externally. And then apply the format [Reason]-[Who reclaim]-[What count?], also i added the 4th item . 1. when the memcg hits its hard_limit > limit_direct_steal > limit_direct_scan 2. when the memcg hits its wmark > wmark_kswapd_steal > wmark_kswapd_scan 3. the global direct reclaim triggers soft_limit pushback > soft_direct_steal > soft_direct_scan 4. hierarchy-triggered direct reclaim > limit_hierarchy_steal > limit_hierarchy_scan 5. the global bg reclaim triggers soft_limit pushback > soft_kswapd_steal > soft_kswapd_scan For both soft_limit reclaim and per-memcg bg reclaim, we don't have hierarchical reclaim. Only hitting the hard_limit of parent will trigger direct reclaim hierarchically on the children. > BTW, your changelog has different name of counters. please fix. sure, will fix that. > > And I'm sorry I'll not be very active for a while. np. --Ying > > Thanks, > -Kame > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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