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 BCB835F0001 for ; Tue, 3 Feb 2009 05:29:37 -0500 (EST) Received: from m5.gw.fujitsu.co.jp ([10.0.50.75]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n13ATUaw022360 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Tue, 3 Feb 2009 19:29:30 +0900 Received: from smail (m5 [127.0.0.1]) by outgoing.m5.gw.fujitsu.co.jp (Postfix) with ESMTP id CF06A45DE57 for ; Tue, 3 Feb 2009 19:29:29 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (s5.gw.fujitsu.co.jp [10.0.50.95]) by m5.gw.fujitsu.co.jp (Postfix) with ESMTP id 9FED245DE4C for ; Tue, 3 Feb 2009 19:29:29 +0900 (JST) Received: from s5.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id 810181DB8040 for ; Tue, 3 Feb 2009 19:29:29 +0900 (JST) Received: from m108.s.css.fujitsu.com (m108.s.css.fujitsu.com [10.249.87.108]) by s5.gw.fujitsu.co.jp (Postfix) with ESMTP id 293491DB8061 for ; Tue, 3 Feb 2009 19:29:29 +0900 (JST) Date: Tue, 3 Feb 2009 19:28:19 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [-mm patch] Show memcg information during OOM (v2) Message-Id: <20090203192819.0c1e0544.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090203101921.GY918@balbir.in.ibm.com> References: <20090203072013.GU918@balbir.in.ibm.com> <20090203072701.GV918@balbir.in.ibm.com> <20090203170427.c6070cda.kamezawa.hiroyu@jp.fujitsu.com> <20090203101921.GY918@balbir.in.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: Andrew Morton , "linux-kernel@vger.kernel.org" , "nishimura@mxp.nes.nec.co.jp" , "lizf@cn.fujitsu.com" , "linux-mm@kvack.org" List-ID: On Tue, 3 Feb 2009 15:49:21 +0530 Balbir Singh wrote: > * KAMEZAWA Hiroyuki [2009-02-03 17:04:27]: > > > On Tue, 3 Feb 2009 12:57:01 +0530 > > Balbir Singh wrote: > > > > > Checkpatch caught an additional space, so here is the patch again > > > > > > > > > Description: Add RSS and swap to OOM output from memcg > > > > > > From: Balbir Singh > > > > > > Changelog v2..v1: > > > > > > 1. Add more information about task's memcg and the memcg > > > over it's limit > > > 2. Print data in KB > > > 3. Move the print routine outside task_lock() > > > 4. Use rcu_read_lock() around cgroup_path, strictly speaking it > > > is not required, but relying on the current memcg implementation > > > is not a good idea. > > > > > > > > > This patch displays memcg values like failcnt, usage and limit > > > when an OOM occurs due to memcg. > > > > > > Thanks go out to Johannes Weiner, Li Zefan, David Rientjes, > > > Kamezawa Hiroyuki, Daisuke Nishimura and KOSAKI Motohiro for > > > review. > > > > > > > IIUC, this oom_kill is serialized by memcg_tasklist mutex. > > Then, you don't have to allocate buffer on stack. > > > > > > > +void mem_cgroup_print_mem_info(struct mem_cgroup *memcg, struct task_struct *p) > > > +{ > > > + struct cgroup *task_cgrp; > > > + struct cgroup *mem_cgrp; > > > + /* > > > + * Need a buffer on stack, can't rely on allocations. > > > + */ > > > + char task_memcg_name[MEM_CGROUP_OOM_BUF_SIZE]; > > > + char memcg_name[MEM_CGROUP_OOM_BUF_SIZE]; > > > + int ret; > > > + > > > > making this as > > > > static char task_memcg_name[PATH_MAX]; > > static char memcg_name[PATH_MAX]; > > > > is ok, I think. and the patch will be more simple. > > > > I am having second thoughts about this one. It introduces a standard > overhead of 2 pages on x86*, while the first one will work for most > cases and all the overhead is on stack, which disappears quickly. > That is the reason I did not do it in the first place and put it as a > NOTE. > But *128* is tooooooo short ;) And, your patch makes "OOM Message Format" unstable. >>From system administration view, it's unacceptable. Not printing name at all is better than "printed out sometimes you lucky" 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