Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760449Ab2JaWPm (ORCPT ); Wed, 31 Oct 2012 18:15:42 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:64810 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752411Ab2JaWPk (ORCPT ); Wed, 31 Oct 2012 18:15:40 -0400 MIME-Version: 1.0 In-Reply-To: <87625r5d44.fsf@sejong.aot.lge.com> References: <871ugg76dn.fsf@sejong.aot.lge.com> <87625r5d44.fsf@sejong.aot.lge.com> Date: Wed, 31 Oct 2012 18:15:39 -0400 Message-ID: Subject: Re: [BUG] perf report: different reports when run on terminal as opposed to script From: Dhaval Giani To: Namhyung Kim Cc: Arnaldo de Melo , mingo@kernel.org, Peter Zijlstra , akshay kumar , LKML Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2286 Lines: 70 On Wed, Oct 31, 2012 at 3:12 AM, Namhyung Kim wrote: > On Tue, 30 Oct 2012 08:05:45 -0400, Dhaval Giani wrote: >> On Tue, Oct 30, 2012 at 3:42 AM, Namhyung Kim wrote: >>> Hi Dhaval, >>> >>> On Mon, 29 Oct 2012 12:45:53 -0400, Dhaval Giani wrote: >>>> On Mon, Oct 29, 2012 at 12:01 PM, Dhaval Giani wrote: >>>>> Hi, >>>>> >>>>> As part of a class assignment I have to collect some performance >>>>> statistics. In order to do so I run >>>>> >>>>> perf record -g >>>>> >>>>> And in another window, I start 200 threads of the load generator >>>>> (which is not recorded by perf) >>>>> >>>>> This generates me statistics that I expect to see, and I am happy. As >>>>> this is academia and a class assignment, I need to collect information >>>>> and analyze it across different setups. Which of course meant I script >>>>> this whole thing, which basically is >>>>> >>>>> for i in all possibilities >>>>> do >>>>> perf record -g & >>>>> WAITPID=$! >>>>> for j in NR_THREADS >>>>> do >>>>> & >>>>> KILLPID=$! >>>>> done >>>>> wait $PID >>> >>> You meant $WAITPID, right? >>> >> >> yes. grrr. I changed the name here to WAITPID for it to be clear and >> that was a fail. (I blame the cold) >> >>> >>>>> kill $KILLPID >>> >>> Doesn't it kill the last load generator only? >>> >>> >> >> Well, this was a bug in me typing the pseudo code. the actual script >> does "$KILLPID $!" > > Okay, so I suspect that it might be affected by the autogroup scheduling > feature since you said running load generators in another window - I > guess it's a terminal. How about running them with setsid? > Why would that affect the data collection for the program being profiled? The time spent (since it is a compute intensive program) in various functions shouldn't change, correct? (Unless I am missing something). /me goes and tries it out Hmm. OK, so that doesn't help. Still the same. Thanks! Dhaval -- 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/