From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753635AbaK0CFg (ORCPT ); Wed, 26 Nov 2014 21:05:36 -0500 Received: from lgeamrelo02.lge.com ([156.147.1.126]:44593 "EHLO lgeamrelo02.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752681AbaK0CFf (ORCPT ); Wed, 26 Nov 2014 21:05:35 -0500 X-Original-SENDERIP: 10.177.222.235 X-Original-MAILFROM: namhyung@gmail.com From: Namhyung Kim To: Kan Liang Cc: acme@kernel.org, jolsa@redhat.com, linux-kernel@vger.kernel.org, ak@linux.intel.com Subject: Re: [PATCH V5 3/3] perf tool: check buildid for symoff References: <1416844829-26945-1-git-send-email-kan.liang@intel.com> <1416844829-26945-3-git-send-email-kan.liang@intel.com> Date: Thu, 27 Nov 2014 11:05:32 +0900 In-Reply-To: <1416844829-26945-3-git-send-email-kan.liang@intel.com> (Kan Liang's message of "Mon, 24 Nov 2014 11:00:29 -0500") Message-ID: <87d289o0sz.fsf@sejong.aot.lge.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Kan, On Mon, 24 Nov 2014 11:00:29 -0500, Kan Liang wrote: > From: Kan Liang > > symoff can support both same binaries and different binaries. However, > the offset may be changed for different binaries. This patch checks the > buildid of perf.data. If they are from different binaries, print a > warning to notify the user. Hmm.. I think that perf diff is supposed to compare performance between different (i.e. modified) binaries. So there's a little point to print the warning IMHO - but I'm not insist it strongly.. Anyway, I think what we really need for the warning is different version of same binary. For example, if data file 1 has DSO A and B, and data file 2 has DSO B and C, we should not consider they're different (unless build-ids of B in data file 1 and 2 are different) since A and C won't affect symoff comparision. Thanks, Namhyung