From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752513AbaIKNnv (ORCPT ); Thu, 11 Sep 2014 09:43:51 -0400 Received: from mail.kernel.org ([198.145.19.201]:51811 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751013AbaIKNnu (ORCPT ); Thu, 11 Sep 2014 09:43:50 -0400 Date: Thu, 11 Sep 2014 10:43:38 -0300 From: Arnaldo Carvalho de Melo To: Mike Galbraith Cc: Namhyung Kim , LKML Subject: Re: perf top -g -U --sort=symbol --children == lalalalala? Message-ID: <20140911134338.GE10158@kernel.org> References: <1410263641.15383.8.camel@marge.simpson.net> <20140909133737.GK2773@kernel.org> <1410439392.20184.17.camel@marge.simpson.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1410439392.20184.17.camel@marge.simpson.net> X-Url: http://acmel.wordpress.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 Em Thu, Sep 11, 2014 at 02:43:12PM +0200, Mike Galbraith escreveu: > On Thu, 2014-09-11 at 17:09 +0900, Namhyung Kim wrote: > > On Tue, Sep 9, 2014 at 10:37 PM, Arnaldo Carvalho de Melo > > wrote: > > > Em Tue, Sep 09, 2014 at 01:54:01PM +0200, Mike Galbraith escreveu: > > >> Seems the now default on --children thingy doesn't like -U much. > > > > > > Namhyung, can you please take a look at this? > > > > So what is the problem here? > > Well, if you don't see anything wrong, I guess nothing at all. :-) I think that when we decide that it is so better to change defaults like we did this time, we should be required to add a big fat warning (a --tui popup, use the first lines on --stdio, etc) about why the default was changed and allow quick, easy opt out, restoring previous behaviour after the user, being warned, knows what to expect, tries it, and then is in a better position to decide if keeping the new default is what is desired. - Arnaldo > > >> Samples: 5K of event 'cycles', Event count (approx.): 2268660922 > > >> Children Self Symbol > > >> + 46.42% 0.04% [k] system_call_fastpath > I'll just turn it off until I figure out what cool stuff this is telling > me. why that symbol becomes the number one hit, and why total% > 100. > To me, it looks like top smoked it's breakfast, went to lala land ;-) Yeah, its confusing, I'll let Namhyung explain it ;-) :-) - Arnaldo