Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751313AbaKEGch (ORCPT ); Wed, 5 Nov 2014 01:32:37 -0500 Received: from lgeamrelo02.lge.com ([156.147.1.126]:54869 "EHLO lgeamrelo02.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750844AbaKEGcg (ORCPT ); Wed, 5 Nov 2014 01:32:36 -0500 X-Original-SENDERIP: 10.177.222.235 X-Original-MAILFROM: namhyung@gmail.com From: Namhyung Kim To: "Liang\, Kan" Cc: "acme\@kernel.org" , "jolsa\@kernel.org" , "linux-kernel\@vger.kernel.org" , "andi\@firstfloor.org" Subject: Re: [PATCH 1/1] perf tools: perf diff for different binaries References: <1414757172-20064-1-git-send-email-kan.liang@intel.com> <87tx2f5xpo.fsf@sejong.aot.lge.com> <37D7C6CF3E00A74B8858931C1DB2F07701653813@SHSMSX103.ccr.corp.intel.com> Date: Wed, 05 Nov 2014 15:32:34 +0900 In-Reply-To: <37D7C6CF3E00A74B8858931C1DB2F07701653813@SHSMSX103.ccr.corp.intel.com> (Kan Liang's message of "Tue, 4 Nov 2014 17:07:43 +0000") Message-ID: <87d292w41p.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 Tue, 4 Nov 2014 17:07:43 +0000, Kan Liang wrote: > Hi Namhyung, > >> > tchain_edit [.] f1 >> > 0.14% 3.913444 tchain_edit [.] f2 >> > 99.82% 1.005478 tchain_edit [.] f3 >> >> Hmm.. I think it should be a default behavior for perf diff, otherwise -s >> symbol is almost meaningless IMHO. > > I think we need both instruction level and function level diff. > For debugging scaling issue, I think we need to do deeper analysis for some > cache or lock issue. The function level is too high granularity. > > The new option can be used to debug scaling regression issue. > If the binary/kernel is updated, it doesn't make sense to compare the > symbol address, since it should be changed. So comparing the function > should be more useful. > > >> What about setting the >> sort_sym.se_collapse in data_process() so that hists__match() can use >> symbol names? > > Yes, we can set it if we only do function level diff. But I'd like to keep > both. So I defined two sort keys. > "symbol" means "symbol address executed at the time of sample " > "symbol_name" means "name of function executed at the time of sample" Hmm.. I don't think the symbol sort key provides the instruction level diff that you want. If it finds a symbol it just use the start address of the symbol, not the exact address of the sample. Am I missing something? 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/