From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757500AbbDVGKS (ORCPT ); Wed, 22 Apr 2015 02:10:18 -0400 Received: from mail-pd0-f170.google.com ([209.85.192.170]:36668 "EHLO mail-pd0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756588AbbDVGKP (ORCPT ); Wed, 22 Apr 2015 02:10:15 -0400 Date: Wed, 22 Apr 2015 15:09:06 +0900 From: Namhyung Kim To: Arnaldo Carvalho de Melo Cc: Ingo Molnar , Peter Zijlstra , Jiri Olsa , LKML , David Ahern , Taeung Song Subject: Re: [PATCH v3] perf tools: Document --children option in more detail Message-ID: <20150422060906.GA21451@danjae.kornet> References: <1429619311-27916-1-git-send-email-namhyung@kernel.org> <20150421154133.GF11111@kernel.org> <20150421161629.GG8483@danjae.kornet> <20150421164640.GG11111@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20150421164640.GG11111@kernel.org> 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 Hi Arnaldo, On Tue, Apr 21, 2015 at 01:46:40PM -0300, Arnaldo Carvalho de Melo wrote: > Em Wed, Apr 22, 2015 at 01:16:29AM +0900, Namhyung Kim escreveu: > > On Tue, Apr 21, 2015 at 12:41:33PM -0300, Arnaldo Carvalho de Melo wrote: > > > > +++ b/tools/perf/Documentation/overhead-calculation.txt > > > I think Ingo suggested that you renamed this file to include the word > > > "callchain" in it, no? looking at "overhead-calculation" I feel like I > > > first have to open it to figure out what kind of overhead is this, > > > perhaps it would be better named: > > > > tools/perf/Documentation/callchain-overhead.txt > > > ? > > > Please see my reply to the Ingo's post. I think he agreed on this name. > > I still find it confusing for the file name, where there is no context, > from just the file name when one does a 'ls tools/perf/Documentatoin' to > figure out about what overhead that is referring to. > > So, perhaps a longer name: > > tools/perf/Documentation/callchain-overhead-calculation.txt > > ? OK, will change. > > Inside perf-{record,top}.txt, yeah, we have context, we know that this > is about post processing, formatting, etc. Right. > > > > > > > +--no-children option on the command line or by adding 'report.children > > > > += false' or 'top.children = false' in the perf config file. > > > > > > One can as well use the OPTION_FOO shortening mechanism and instead use: > > > > > > perf report --no-ch > > > > > > Which is enough to disambiguate it from "--no-column-widths" and "--no-cpu". > > > > Are you saying that you want to add the short form instead of the full > > --no-chlidren name? I think we need to verbose in the manpage at > > least and it might not work in the future if some --chxxx option is > > added. > > Perhaps: > > "--no-children option on the command line or by adding 'report.children = false' > or 'top.children = false' in the perf config file. > > A shorter form on the command line can be used, for instance '--no-ch' > is unambiguous at the time of this writing." I don't think it belongs here. The shorter form is not only for the --children, so it should be described in different place. > > > > > diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt > > > > index 4879cf638824..b7bb298deee3 100644 > > > > --- a/tools/perf/Documentation/perf-report.txt > > > > +++ b/tools/perf/Documentation/perf-report.txt > > > > @@ -193,6 +193,7 @@ OPTIONS > > > > Accumulate callchain of children to parent entry so that then can > > > > show up in the output. The output will have a new "Children" column > > > > and will be sorted on the data. It requires callchains are recorded. > > > > + See the `overhead calculation' section for more details. > > > > > > `callchain overhead' > > > > Do you prefer this name to 'overhead calculation'? For me, it looks > > It is ok with me "overhead calculation", as mentioned previously in this > message, the context in this perf-report.txt file should make it clear > that the overhead is about callchains. OK, I'll leave it as is. Thanks, Namhyung > > > like saying about how much overhead will be added if we enabled > > callchains at perf record time or processing them at perf report time. > > Ok. > > - Arnaldo