From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757695Ab3JKM7l (ORCPT ); Fri, 11 Oct 2013 08:59:41 -0400 Received: from mail-ea0-f169.google.com ([209.85.215.169]:33903 "EHLO mail-ea0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751751Ab3JKM7j (ORCPT ); Fri, 11 Oct 2013 08:59:39 -0400 Date: Fri, 11 Oct 2013 14:59:35 +0200 From: Ingo Molnar To: Namhyung Kim Cc: Jiri Olsa , Arnaldo Carvalho de Melo , Peter Zijlstra , Paul Mackerras , Namhyung Kim , LKML , Linus Torvalds , Frederic Weisbecker Subject: Re: [PATCHSET 0/8] perf tools: Fix scalability problem on callchain merging (v5) Message-ID: <20131011125935.GA10634@gmail.com> References: <1381468543-25334-1-git-send-email-namhyung@kernel.org> <20131011055829.GA4975@gmail.com> <20131011073448.GA11064@krava.redhat.com> <8761t4cizo.fsf@sejong.aot.lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8761t4cizo.fsf@sejong.aot.lge.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Namhyung Kim wrote: > Hi Jiri, > > On Fri, 11 Oct 2013 09:34:48 +0200, Jiri Olsa wrote: > > On Fri, Oct 11, 2013 at 07:58:29AM +0200, Ingo Molnar wrote: > >> > >> * Namhyung Kim wrote: > >> > >> > Hello, > >> > > >> > This is a new version of callchain improvement patchset. Basically > >> > it's almost same as v4 but rebased on current acme/perf/core and some > >> > functions are renamed as Frederic requested. > >> > > >> > Now I'm hunting down a bug in 'perf report -s sym' which was found > >> > during the test, but I think it's not related to this change as it can > >> > be reproduced in earlier versions too. > >> > > >> > I put this series on 'perf/callchain-v5' branch in my tree > >> > > >> > git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git > >> > > >> > Any comments are welcome, thanks. > >> > >> One thing I noticed about call-graph profiling: > >> > >> comet:~/tip/tools/perf> ./perf record -g ~/hackbench 10 > >> callchain: Unknown -g option value: /home/mingo/hackbench > >> > >> I think a naked -g used to work just fine in the past. Even if such an > >> error is displayed the output is very unhelpful, it does does a full > >> perf-record options dump (unnecessary), the bit that is helpful is hidden > >> amongst many other options: > >> > >> -g, --call-graph > >> do call-graph (stack chain/backtrace) recording: [fp] dwarf > >> > >> and it took me two reads to see that I should specify 'fp'. The '[fp]' > >> indicates that fp is the default - but that does not appear to be working. > > > > '-g' takes optional parameter, so having it in front of > > non option string is causing the error, you could use: > > > > ./perf record -g -- ~/hackbench 10 > > Yes, I think this is an unfortunate change to break some user's scripts. > It'd be great if it detect whether the next argument belongs to the > option, or if not, pass it to next normally - but it seems to be not so > simple IMHO. So, why not keep -g as a shortcut to whatever default call-graph profiling we want to provide (note, this does not mean it always has to be 'fp'), and use --call-graph for more specific variants? a .perfconfig value could even set the default for '-g', so that you don't have to type '--call-graph dwarf' all the time. Thanks, Ingo