From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id 2F0336B0012 for ; Thu, 26 May 2011 05:06:23 -0400 (EDT) Date: Thu, 26 May 2011 11:05:38 +0200 From: Johannes Weiner Subject: Re: [PATCH] memcg: fix typo in the soft_limit stats. Message-ID: <20110526090538.GA19082@cmpxchg.org> References: <1305583230-2111-1-git-send-email-yinghan@google.com> <20110516231512.GW16531@cmpxchg.org> <20110516171820.124a8fbc.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110516171820.124a8fbc.akpm@linux-foundation.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Ying Han , KOSAKI Motohiro , Minchan Kim , Daisuke Nishimura , Balbir Singh , Tejun Heo , Pavel Emelyanov , KAMEZAWA Hiroyuki , Li Zefan , Mel Gorman , Christoph Lameter , Rik van Riel , Hugh Dickins , Michal Hocko , Dave Hansen , Zhu Yanhai , linux-mm@kvack.org On Mon, May 16, 2011 at 05:18:20PM -0700, Andrew Morton wrote: > On Mon, 16 May 2011 17:05:02 -0700 > Ying Han wrote: > > > On Mon, May 16, 2011 at 4:15 PM, Johannes Weiner wrote: > > > > > On Mon, May 16, 2011 at 03:00:30PM -0700, Ying Han wrote: > > > > This fixes the typo in the memory.stat including the following two > > > > stats: > > > > > > > > $ cat /dev/cgroup/memory/A/memory.stat > > > > total_soft_steal 0 > > > > total_soft_scan 0 > > > > > > > > And change it to: > > > > > > > > $ cat /dev/cgroup/memory/A/memory.stat > > > > total_soft_kswapd_steal 0 > > > > total_soft_kswapd_scan 0 > > > > > > > > Signed-off-by: Ying Han > > > > > > I am currently proposing and working on a scheme that makes the soft > > > limit not only a factor for global memory pressure, but for > > > hierarchical reclaim in general, to prefer child memcgs during reclaim > > > that are in excess of their soft limit. > > > > > > Because this means prioritizing memcgs over one another, rather than > > > having explicit soft limit reclaim runs, there is no natural counter > > > for pages reclaimed due to the soft limit anymore. > > > > > > Thus, for the patch that introduces this counter: > > > > > > Nacked-by: Johannes Weiner > > > > > > > This patch is fixing a typo of the stats being integrated into mmotm. Does > > it make sense to fix the > > existing stats first while we are discussing other approaches? > > > > It would be quite bad to add new userspace-visible stats and to then > take them away again. > > But given that memcg-add-stats-to-monitor-soft_limit-reclaim.patch is > queued for 2.6.39-rc1, we could proceed with that plan and then make > sure that Johannes's changes are merged either prior to 2.6.40 or > they are never merged at all. I am on it, but I don't think I can get them into shape and rudimentally benchmarked until the merge window is closed. So far I found nothing that would invalidate the design or have measurable impact on non-memcg systems. Then again, I suck at constructing tests, and have only limited machinery available. If people are interested and would like to help out verifying the changes, I can send an updated and documented version of the series that should be easier to understand. > Or we could just leave out the stats until we're sure. Not having them > for a while is not as bad as adding them and then removing them. I am a bit unsure as to why there is a sudden rush with those statistics now. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org