From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753787AbZALBKE (ORCPT ); Sun, 11 Jan 2009 20:10:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751511AbZALBJx (ORCPT ); Sun, 11 Jan 2009 20:09:53 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:63825 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751424AbZALBJx (ORCPT ); Sun, 11 Jan 2009 20:09:53 -0500 Message-ID: <496A982E.3020103@cn.fujitsu.com> Date: Mon, 12 Jan 2009 09:09:02 +0800 From: Li Zefan User-Agent: Thunderbird 2.0.0.9 (X11/20071115) MIME-Version: 1.0 To: paulmck@linux.vnet.ibm.com CC: Frederic Weisbecker , Ingo Molnar , LKML , Steven Rostedt Subject: Re: [PATCH] rcu: convert rcupreempt trace to seq file References: <496852DE.7080802@cn.fujitsu.com> <20090110223151.GD7061@linux.vnet.ibm.com> <20090111013940.GL12885@elte.hu> <20090111050129.GA6131@nowhere> <20090111051604.GF7061@linux.vnet.ibm.com> In-Reply-To: <20090111051604.GF7061@linux.vnet.ibm.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 >> The debugfs and seqfile handling and handled in the statistical >> tracing engine. >> >> You just have to provide an iterator for your stat entries through two callbacks: >> >> _ stat_start() -> gives the first entry >> _ stat_next() -> iterates over the next entry >> >> And an output callback >> >> _ stat_show() -> print one entry from your stat list >> >> And two optional things: >> >> _ stat_cmp() -> compare two entries, useful if you want your stats to be sorted >> _ stat_headers() -> provide the first line in your stat file, typically to describe your columns >> >> The last thing you need is to give a name to your trace file. >> You will retrieve it into /debugfs/tracing/trace_stat/your_file_name as a current snapshot >> of your stats. >> >> It is currently used by the branch tracer, and by a pending patch for a new workqueue >> tracer which will provide you a simple example. >> >> If you have any question about how to use it, don't hesitate to ask. > > Li Zefan, is this something you would be willing to try? Sounds like > it might be a good addition. > Sure, I'll try. :)