From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx168.postini.com [74.125.245.168]) by kanga.kvack.org (Postfix) with SMTP id 8BD2B6B004F for ; Wed, 7 Dec 2011 20:48:18 -0500 (EST) Received: from m1.gw.fujitsu.co.jp (unknown [10.0.50.71]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 405B93EE0BC for ; Thu, 8 Dec 2011 10:48:16 +0900 (JST) Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 26AD12E6944 for ; Thu, 8 Dec 2011 10:48:16 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 0DCA22E6942 for ; Thu, 8 Dec 2011 10:48:16 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id F1D8D1DB8051 for ; Thu, 8 Dec 2011 10:48:15 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.240.81.145]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id A68031DB804D for ; Thu, 8 Dec 2011 10:48:15 +0900 (JST) Date: Thu, 8 Dec 2011 10:47:05 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH] oom: add tracepoints for oom_score_adj Message-Id: <20111208104705.b2e50039.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <4EDF99B2.6040007@jp.fujitsu.com> References: <20111207095434.5f2fed4b.kamezawa.hiroyu@jp.fujitsu.com> <4EDF99B2.6040007@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: KOSAKI Motohiro Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, rientjes@google.com, dchinner@redhat.com On Wed, 07 Dec 2011 11:52:02 -0500 KOSAKI Motohiro wrote: > On 12/6/2011 7:54 PM, KAMEZAWA Hiroyuki wrote: > >>From 28189e4622fd97324893a0b234183f64472a54d6 Mon Sep 17 00:00:00 2001 > > From: KAMEZAWA Hiroyuki > > Date: Wed, 7 Dec 2011 09:58:16 +0900 > > Subject: [PATCH] oom: trace point for oom_score_adj > > > > oom_score_adj is set to prevent a task from being killed by OOM-Killer. > > Some daemons sets this value and their children inerit it sometimes. > > Because inheritance of oom_score_adj is done automatically, users > > can be confused at seeing the value and finds it's hard to debug. > > > > This patch adds trace point for oom_score_adj. This adds 3 trace > > points. at > > - update oom_score_adj > > > > - fork() > > - rename task->comm(typically, exec()) > > I don't think they have oom specific thing. Can you please add generic fork and > task rename tracepoint instead? > I think it makes oom-targeted debug difficult. This tracehook using task->signal->oom_score_adj as filter. This reduces traces much and makes debugging easier. If you need another trace point for other purpose, another trace point should be better. For generic purpose, oom_socre_adj filtering will not be necessary. > > > > Outputs will be following. > > bash-2404 [006] 199.620841: oom_score_adj_update: task 2404[bash] updates oom_score_ad j=-1000 > > "task 2404[bash]" don't look good to me. > > In almost case, we use either > > - [pid] comm > - pid:comm > - comm:pid > - comm-pid (ftrace specific) > > Why do we need to introduce alternative printing style? > No reason. ok, I'll fix. 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org