From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id BA77C6B01E7 for ; Thu, 3 Jun 2010 02:44:46 -0400 (EDT) Received: from kpbe19.cbf.corp.google.com (kpbe19.cbf.corp.google.com [172.25.105.83]) by smtp-out.google.com with ESMTP id o536igL3012989 for ; Wed, 2 Jun 2010 23:44:42 -0700 Received: from pxi10 (pxi10.prod.google.com [10.243.27.10]) by kpbe19.cbf.corp.google.com with ESMTP id o536ieT9010793 for ; Wed, 2 Jun 2010 23:44:41 -0700 Received: by pxi10 with SMTP id 10so3280280pxi.21 for ; Wed, 02 Jun 2010 23:44:40 -0700 (PDT) Date: Wed, 2 Jun 2010 23:44:33 -0700 (PDT) From: David Rientjes Subject: Re: [patch -mm 08/18] oom: badness heuristic rewrite In-Reply-To: <20100603090552.1206dfb4.kamezawa.hiroyu@jp.fujitsu.com> Message-ID: References: <20100601074620.GR9453@laptop> <20100602222347.F527.A69D9226@jp.fujitsu.com> <20100603090552.1206dfb4.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro , Nick Piggin , Andrew Morton , Rik van Riel , Oleg Nesterov , Balbir Singh , linux-mm@kvack.org List-ID: On Thu, 3 Jun 2010, KAMEZAWA Hiroyuki wrote: > > > > I'm glad you asked that because some recent conversation has been > > > > slightly confusing to me about how this affects the desktop; this rewrite > > > > significantly improves the oom killer's response for desktop users. The > > > > core ideas were developed in the thread from this mailing list back in > > > > February called "Improving OOM killer" at > > > > http://marc.info/?t=126506191200004&r=4&w=2 -- users constantly report > > > > that vital system tasks such as kdeinit are killed whenever a memory > > > > hogging task is forked either intentionally or unintentionally. I argued > > > > for a while that KDE should be taking proper precautions by adjusting its > > > > own oom_adj score and that of its forked children as it's an inherited > > > > value, but I was eventually convinced that an overall improvement to the > > > > heuristic must be made to kill a task that was known to free a large > > > > amount of memory that is resident in RAM and that we have a consistent way > > > > of defining oom priorities when a task is run uncontained and when it is a > > > > member of a memcg or cpuset (or even mempolicy now), even in the case when > > > > it's contained out from under the task's knowledge. When faced with > > > > memory pressure from an out of control or memory hogging task on the > > > > desktop, the oom killer now kills it instead of a vital task such as an X > > > > server (and oracle, webserver, etc on server platforms) because of the use > > > > of the task's rss instead of total_vm statistic. > > > > > > The above story teach us oom-killer need some improvement. but it haven't > > > prove your patches are correct solution. that's why you got to ask testing way. > > > > > > > I would consider what I said above, "when faced with memory pressure from > > an out of control or memory hogging task on the desktop, the oom killer > > now kills it instead of a vital task such as an X server because of the > > use of the task's rss instead of total_vm statistic" as an improvement > > over killing X in those cases which it currently does. How do you > > disagree? > > > > It was you who disagree using RSS for oom killing in the last winter. > By what observation did you change your mind ? (Don't take this as criticism. > I'm just curious.) > The fact that when I ran the new heuristic it improved the oom killer on my desktop to save KDE and kill a memory-hogging task that stressed it. I became supportive of the idea through the discussion that went on specifically about using total_vm as a baseline and was convinced that it was better to use rss as well as a more powerful user interface so that admins could more accurately set their oom kill priorities even when their cpuset, memcg, or mempolicy placement was changed out from under it. > My stand point: > I don't like the new interface at all but welcome the concept for using RSS . Using rss is not a new interface. -- 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/ . Don't email: email@kvack.org