From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx161.postini.com [74.125.245.161]) by kanga.kvack.org (Postfix) with SMTP id 2222A6B004A for ; Wed, 25 Apr 2012 10:42:32 -0400 (EDT) Message-ID: <4F980D32.8020309@redhat.com> Date: Wed, 25 Apr 2012 10:41:54 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: Over-eager swapping References: <20120423092730.GB20543@alpha.arachsys.com> In-Reply-To: <20120423092730.GB20543@alpha.arachsys.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Richard Davies Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Minchan Kim , Wu Fengguang , Balbir Singh , Christoph Lameter , Lee Schermerhorn , Chris Webb On 04/23/2012 05:27 AM, Richard Davies wrote: > The rrd graphs at http://imgur.com/a/Fklxr show a typical incident. > > We estimate memory used from /proc/meminfo as: > > = MemTotal - MemFree - Buffers + SwapTotal - SwapFree > > The first rrd shows memory used increasing as a VM starts, but not getting > near the 64GB of physical RAM. > > The second rrd shows the heavy swapping this VM start caused. > > The third rrd shows a multi-gigabyte jump in swap used = SwapTotal - SwapFree > > The fourth rrd shows the large load spike (from 1 to 15) caused by this swap > storm. These are exactly the kind of swap storms that led me make the VM tweaks that got merged into 3.4-rc :) See these commits: fe2c2a106663130a5ab45cb0e3414b52df2fff0c 7be62de99adcab4449d416977b4274985c5fe023 aff622495c9a0b56148192e53bdec539f5e147f2 1480de0340a8d5f094b74d7c4b902456c9a06903 496b919b3bdd957d4b1727df79bfa3751bced1c1 -- 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