From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753592AbcAGWAi (ORCPT ); Thu, 7 Jan 2016 17:00:38 -0500 Received: from mail-wm0-f51.google.com ([74.125.82.51]:37472 "EHLO mail-wm0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753256AbcAGWAh (ORCPT ); Thu, 7 Jan 2016 17:00:37 -0500 MIME-Version: 1.0 In-Reply-To: <20160107215945.GA19314@kernel.org> References: <20160107215945.GA19314@kernel.org> Date: Thu, 7 Jan 2016 14:00:35 -0800 Message-ID: Subject: Re: [RFC] perf record: missing buildid for callstack modules From: Stephane Eranian To: Arnaldo Carvalho de Melo Cc: LKML , Jiri Olsa , Namhyung Kim , Peter Zijlstra , Ingo Molnar , Adrian Hunter , "ak@linux.intel.com" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 7, 2016 at 1:59 PM, Arnaldo Carvalho de Melo wrote: > Em Thu, Jan 07, 2016 at 01:56:14PM -0800, Stephane Eranian escreveu: >> Hi, >> >> Whenever you do: >> >> $ perf record -g -a sleep 10 >> >> Perf will collect the callstack for each sample. At the end of the >> run, perf record >> adds the buildid for all dso with at least one sample. But when it does this, it >> only looks at the sampled IP and ignore the modules traversed by the callstack. >> That means that, it is not possible to uniquely identify the modules executed, >> unless they had at least one IP sample captured. But this is not >> always the case. >> >> How about providing an option to perf record to force collecting >> buildid for all IPs >> captured in the callstack? I understand that would cost more at the end of the >> collection, but this would be beneficial to several monitoring scenarios. > > I agree, would consider applying a patch that provides the option but > does not do this by default. > I agree, not the default.