From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id B60D36B0071 for ; Thu, 21 Jan 2010 18:57:42 -0500 (EST) Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o0LNvdb2019942 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Fri, 22 Jan 2010 08:57:39 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 5CE0A45DE4E for ; Fri, 22 Jan 2010 08:57:39 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 3A29745DE51 for ; Fri, 22 Jan 2010 08:57:39 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 259AC1DB8038 for ; Fri, 22 Jan 2010 08:57:39 +0900 (JST) Received: from m106.s.css.fujitsu.com (m106.s.css.fujitsu.com [10.249.87.106]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id A444D1DB803C for ; Fri, 22 Jan 2010 08:57:38 +0900 (JST) Date: Fri, 22 Jan 2010 08:54:20 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH] oom-kill: add lowmem usage aware oom kill handling Message-Id: <20100122085420.38d8adea.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <4B5872EC.5040603@linux.vnet.ibm.com> References: <20100121145905.84a362bb.kamezawa.hiroyu@jp.fujitsu.com> <4B5872EC.5040603@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: balbir@linux.vnet.ibm.com Cc: "linux-mm@kvack.org" , "akpm@linux-foundation.org" , rientjes@google.com, minchan.kim@gmail.com, "linux-kernel@vger.kernel.org" List-ID: On Thu, 21 Jan 2010 20:59:48 +0530 Balbir Singh wrote: > On Thursday 21 January 2010 11:29 AM, KAMEZAWA Hiroyuki wrote: > > A patch for avoiding oom-serial-killer at lowmem shortage. > > Patch is onto mmotm-2010/01/15 (depends on mm-count-lowmem-rss.patch) > > Tested on x86-64/SMP + debug module(to allocated lowmem), works well. > > > > == > > From: KAMEZAWA Hiroyuki > > > > One cause of OOM-Killer is memory shortage in lower zones. > > (If memory is enough, lowmem_reserve_ratio works well. but..) > > > > In lowmem-shortage oom-kill, oom-killer choses a vicitim process > > on their vm size. But this kills a process which has lowmem memory > > only if it's lucky. At last, there will be an oom-serial-killer. > > > > Now, we have per-mm lowmem usage counter. We can make use of it > > to select a good? victim. > > Have you seen any use cases that need this change? Or is it mostly via > code review and to utilize the availability of lowmem rss? Do we often > run into lowmem shortage triggering OOM? > - I saw lowmem OOM killer very frequently on x86-32 box in my cusotmers. - I saw lowmem OOM killer somemtimes on ia64 box in my customers. I know this helps oom handling in x86-32+Highmem environments. For my _new_ customers, almost all devices are connected to 64bit PCI bus. So, this is not for my customers ;) But OOM-Killer should handle this case. Thanks, -Kame -- 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