From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751707AbaK1Jtm (ORCPT ); Fri, 28 Nov 2014 04:49:42 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38468 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751564AbaK1Jtj (ORCPT ); Fri, 28 Nov 2014 04:49:39 -0500 Date: Fri, 28 Nov 2014 10:49:26 +0100 From: Jiri Olsa To: "Liang, Kan" Cc: Namhyung Kim , "acme@kernel.org" , "linux-kernel@vger.kernel.org" , "ak@linux.intel.com" Subject: Re: [PATCH V5 3/3] perf tool: check buildid for symoff Message-ID: <20141128094926.GB27703@krava.brq.redhat.com> References: <1416844829-26945-1-git-send-email-kan.liang@intel.com> <1416844829-26945-3-git-send-email-kan.liang@intel.com> <87d289o0sz.fsf@sejong.aot.lge.com> <37D7C6CF3E00A74B8858931C1DB2F07701676CB2@SHSMSX103.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <37D7C6CF3E00A74B8858931C1DB2F07701676CB2@SHSMSX103.ccr.corp.intel.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 27, 2014 at 02:09:51PM +0000, Liang, Kan wrote: > > > > 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. that sounds good to me > > > > It looks good. > But I still slightly prefer to warn/inform the user if there are any different dsos, > not just from common part. But it's not a strong option. > I'd like to hear from others. > > Arnaldo? Jirka? sorry for late reply.. anyway like I said in the other email --- IMO one (WARN_ONCE style) warning by default if we see buildids discrepancy and detailed comparison for --verbose --- I think the breakage of the check (that Namhyung described) could be mentioned/labeled somehow as serious issue in the warning and we could also 'inform' about "any different dsos" as you mentioned jirka > > Thanks, > Kan > > > Thanks, > > Namhyung