From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx107.postini.com [74.125.245.107]) by kanga.kvack.org (Postfix) with SMTP id 9E54A6B0170 for ; Thu, 15 Dec 2011 03:55:48 -0500 (EST) Received: by qan41 with SMTP id 41so140684qan.14 for ; Thu, 15 Dec 2011 00:55:47 -0800 (PST) Date: Thu, 15 Dec 2011 00:55:44 -0800 (PST) From: David Rientjes Subject: Re: [PATCH v4] oom: add trace points for debugging. In-Reply-To: <20111213181225.673e19db.kamezawa.hiroyu@jp.fujitsu.com> Message-ID: References: <20111213181225.673e19db.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: KAMEZAWA Hiroyuki Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, KOSAKI Motohiro , Andrew Morton On Tue, 13 Dec 2011, KAMEZAWA Hiroyuki wrote: > Subject: [PATCH] tracepoint: add tracepoints for debugging oom_score_adj. > > oom_score_adj is used for guarding processes from OOM-Killer. One of problem > is that it's inherited at fork(). When a daemon set oom_score_adj and > make children, it's hard to know where the value is set. > > This patch adds some tracepoints useful for debugging. This patch adds > 3 trace points. > - creating new task > - renaming a task (exec) > - set oom_score_adj > > To debug, users need to enable some trace pointer. Maybe filtering is useful as > > # EVENT=/sys/kernel/debug/tracing/events/task/ > # echo "oom_score_adj != 0" > $EVENT/task_newtask/filter > # echo "oom_score_adj != 0" > $EVENT/task_rename/filter > # echo 1 > $EVENT/enable > # EVENT=/sys/kernel/debug/tracing/events/oom/ > # echo 1 > $EVENT/enable > > output will be like this. > # grep oom /sys/kernel/debug/tracing/trace > bash-7699 [007] d..3 5140.744510: oom_score_adj_update: pid=7699 comm=bash oom_score_adj=-1000 > bash-7699 [007] ...1 5151.818022: task_newtask: pid=7729 comm=bash clone_flags=1200011 oom_score_adj=-1000 > ls-7729 [003] ...2 5151.818504: task_rename: pid=7729 oldcomm=bash newcomm=ls oom_score_adj=-1000 > bash-7699 [002] ...1 5175.701468: task_newtask: pid=7730 comm=bash clone_flags=1200011 oom_score_adj=-1000 > grep-7730 [007] ...2 5175.701993: task_rename: pid=7730 oldcomm=bash newcomm=grep oom_score_adj=-1000 > > Signed-off-by: KAMEZAWA Hiroyuki Acked-by: David Rientjes Thanks for being persistant with this! -- 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