Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758703Ab3GaAv6 (ORCPT ); Tue, 30 Jul 2013 20:51:58 -0400 Received: from LGEMRELSE1Q.lge.com ([156.147.1.111]:43182 "EHLO LGEMRELSE1Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753638Ab3GaAv4 (ORCPT ); Tue, 30 Jul 2013 20:51:56 -0400 X-AuditID: 9c93016f-b7b50ae0000021a9-05-51f85faa510e Message-ID: <51F85FAA.2090400@lge.com> Date: Wed, 31 Jul 2013 09:51:54 +0900 From: Namhyung Kim User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/20130509 Thunderbird/17.0.6 MIME-Version: 1.0 To: Arnaldo Carvalho de Melo CC: Namhyung Kim , Peter Zijlstra , Paul Mackerras , Ingo Molnar , LKML , Steven Rostedt , Frederic Weisbecker , Jiri Olsa , David Ahern , Stephane Eranian , Jeremy Eder Subject: Re: [PATCH 01/17] perf util: Save pid-cmdline mapping into tracing header References: <1375175954-798-1-git-send-email-namhyung@kernel.org> <1375175954-798-2-git-send-email-namhyung@kernel.org> <20130730132839.GA2607@ghostprotocols.net> In-Reply-To: <20130730132839.GA2607@ghostprotocols.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1153 Lines: 29 Hi Arnaldo, 2013-07-30 오후 10:28, Arnaldo Carvalho de Melo 쓴 글: > Em Tue, Jul 30, 2013 at 06:18:58PM +0900, Namhyung Kim escreveu: >> From: Namhyung Kim >> >> Current trace info data lacks the saved cmdline mapping which is >> needed for pevent to find out the comm of a task. Add this and bump >> up the version number so that perf can determine its presence when >> reading. > > Can't we get this from the PERF_RECORD_COMM synthesized at the beginning > of the session + the kernel generated ones for new threads? > > We would just call machine__find_thread() and use thread->comm, etc, no? Yes, I think it's doable. However it needs an additional perf event only to generate the COMM events. So I decided not to do it and reused saved cmdline info from ftrace. But IIUC it also has a problem of possible information loss due to the size of table. Thanks, Namhyung -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/