From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from zps76.corp.google.com (zps76.corp.google.com [172.25.146.76]) by smtp-out.google.com with ESMTP id lB1J2bi4005992 for ; Sat, 1 Dec 2007 11:02:37 -0800 Received: from py-out-1112.google.com (pyia25.prod.google.com [10.34.253.25]) by zps76.corp.google.com with ESMTP id lB1J2aim019063 for ; Sat, 1 Dec 2007 11:02:36 -0800 Received: by py-out-1112.google.com with SMTP id a25so6092775pyi for ; Sat, 01 Dec 2007 11:02:36 -0800 (PST) Message-ID: <6599ad830712011102h3bbfd7e6lc5c448cd8efa3158@mail.gmail.com> Date: Sat, 1 Dec 2007 11:02:32 -0800 From: "Paul Menage" Subject: Re: What can we do to get ready for memory controller merge in 2.6.25 In-Reply-To: <20071201133652.6888a717@bree.surriel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <474ED005.7060300@linux.vnet.ibm.com> <200711301311.48291.nickpiggin@yahoo.com.au> <6599ad830711302339v1f92af40v85e89484a8a6575e@mail.gmail.com> <47512E65.9030803@linux.vnet.ibm.com> <20071201133652.6888a717@bree.surriel.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: balbir@linux.vnet.ibm.com, Nick Piggin , Linux Memory Management List , Andrew Morton , linux kernel mailing list , Peter Zijlstra , Hugh Dickins , Lee Schermerhorn , KAMEZAWA Hiroyuki , Pavel Emelianov , YAMAMOTO Takashi , Christoph Lameter , "Martin J. Bligh" , Andy Whitcroft , Srivatsa Vaddagiri List-ID: On Dec 1, 2007 10:36 AM, Rik van Riel wrote: > > With the /proc/refaults info, we can measure how much extra > memory each process group needs, if any. What's the status of that? It looks as though it would be better than the "accessed in the last N seconds" metric that we've been playing with, although it's possibly more intrusive? Would it be practical to keep a non-resident set for each cgroup? > > As for how much memory a process group needs, at pageout time > we can check the fraction of pages that are accessed. If 60% > of the pages were recently accessed at pageout time and this > process group is spending little or no time waiting for refaults, > 40% of the pages are *not* recently accessed and we can probably > reduce the amount of memory assigned to this group. It would probably be better to reduce its background-reclaim high watermark than to reduce its limit. If you do the latter, you risk triggering an OOM in the cgroup if it turns out that it did need all that memory after all. Paul -- 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