From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755880AbZEYD4R (ORCPT ); Sun, 24 May 2009 23:56:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751960AbZEYD4C (ORCPT ); Sun, 24 May 2009 23:56:02 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:57624 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751984AbZEYD4B (ORCPT ); Sun, 24 May 2009 23:56:01 -0400 Message-ID: <8F90215D2B2846BDBCD0FACB72CD2B6C@zhaoleiwin> From: "Zhaolei" To: "Frederic Weisbecker" Cc: "Steven Rostedt" , "Ingo Molnar" , "Tom Zanussi" , "LKML" References: <4A14FDFE.2080402@cn.fujitsu.com> <4A16788F.2060802@cn.fujitsu.com> <4A1678F1.1060706@cn.fujitsu.com> <20090524204240.GB6471@nowhere> Subject: Re: [PATCH v2 1/2] ftrace: Add task_comm support for trace_event Date: Mon, 25 May 2009 11:54:27 +0800 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by alpha.home.local id n4P3uM7M026691 * From: "Frederic Weisbecker" > Hi, > > > On Fri, May 22, 2009 at 06:05:37PM +0800, Zhaolei wrote: >> If we use trace_event alone(without function trace, .etc), >> it can't output enough task command information. >> >> Before patch: >> # echo 1 > debugfs/tracing/events/sched/sched_switch/enable >> # cat debugfs/tracing/trace >> # tracer: nop >> # >> # TASK-PID CPU# TIMESTAMP FUNCTION >> # | | | | | >> <...>-2289 [000] 526276.724790: sched_switch: task bash:2289 [120] ==> sshd:2287 [120] >> <...>-2287 [000] 526276.725231: sched_switch: task sshd:2287 [120] ==> bash:2289 [120] >> <...>-2289 [000] 526276.725452: sched_switch: task bash:2289 [120] ==> sshd:2287 [120] >> <...>-2287 [000] 526276.727181: sched_switch: task sshd:2287 [120] ==> swapper:0 [140] >> -0 [000] 526277.032734: sched_switch: task swapper:0 [140] ==> events/0:5 [115] >> <...>-5 [000] 526277.032782: sched_switch: task events/0:5 [115] ==> swapper:0 [140] >> ... >> >> After patch: >> # tracer: nop >> # >> # TASK-PID CPU# TIMESTAMP FUNCTION >> # | | | | | >> bash-2269 [000] 527347.989229: sched_switch: task bash:2269 [120] ==> sshd:2267 [120] >> sshd-2267 [000] 527347.990960: sched_switch: task sshd:2267 [120] ==> bash:2269 [120] >> bash-2269 [000] 527347.991143: sched_switch: task bash:2269 [120] ==> sshd:2267 [120] >> sshd-2267 [000] 527347.992959: sched_switch: task sshd:2267 [120] ==> swapper:0 [140] >> -0 [000] 527348.531989: sched_switch: task swapper:0 [140] ==> events/0:5 [115] >> events/0-5 [000] 527348.532115: sched_switch: task events/0:5 [115] ==> swapper:0 [140] >> ... >> >> Signed-off-by: Zhao Lei > > > Thanks! > This is fine but I think it can be factorized. > > You could call start_cmdline_record() from > > ftrace_raw_reg_event_##call() > > and the stop in > > ftrace_raw_unreg_event_##call() > > No? Hello, Frederic Thanks for your advice. Actually, I considered to put start_cmdline_record() into ftrace_raw_reg_event_##call(), but finally I selected to put it into tracing_start_cmdline_record(). IMHO, we have following reason: 1: It can make source more readable. Read function is more easy than read macro. 2: These two way have same performance. 3: Put start_cmdline_record() into ftrace_event_enable_disable() will reduce binary file size than ftrace_raw_reg_event_##call(). So I think put start_cmdline_record() into ftrace_event_enable_disable() maybe better. What is your opinion? Thanks Zhaolei {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I