From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752834Ab1LHRds (ORCPT ); Thu, 8 Dec 2011 12:33:48 -0500 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:42153 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752369Ab1LHRdq (ORCPT ); Thu, 8 Dec 2011 12:33:46 -0500 Message-ID: <4EE0F4EF.4010301@jp.fujitsu.com> Date: Thu, 08 Dec 2011 12:33:35 -0500 From: KOSAKI Motohiro User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:8.0) Gecko/20111105 Thunderbird/8.0 MIME-Version: 1.0 To: kamezawa.hiroyu@jp.fujitsu.com CC: linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, rientjes@google.com, dchinner@redhat.com Subject: Re: [PATCH] oom: add tracepoints for oom_score_adj References: <20111207095434.5f2fed4b.kamezawa.hiroyu@jp.fujitsu.com> <4EDF99B2.6040007@jp.fujitsu.com> <20111208104705.b2e50039.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20111208104705.b2e50039.kamezawa.hiroyu@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/7/2011 8:47 PM, KAMEZAWA Hiroyuki wrote: > 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. see Documentation/trace/event.txt 5. Event filgtering Now, both ftrace and perf have good filter feature. Isn't this enough?