Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753240AbZF0H5U (ORCPT ); Sat, 27 Jun 2009 03:57:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751794AbZF0H5N (ORCPT ); Sat, 27 Jun 2009 03:57:13 -0400 Received: from hera.kernel.org ([140.211.167.34]:39727 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751287AbZF0H5M (ORCPT ); Sat, 27 Jun 2009 03:57:12 -0400 Subject: Re: [tip:perfcounters/urgent] perf stat: Add -n/--null option to run without counters From: Jaswinder Singh Rajput To: mingo@redhat.com, hpa@zytor.com, paulus@samba.org, acme@redhat.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, efault@gmx.de, tglx@linutronix.de, mingo@elte.hu Cc: linux-tip-commits@vger.kernel.org In-Reply-To: References:

Content-Type: text/plain Date: Sat, 27 Jun 2009 13:26:24 +0530 Message-Id: <1246089384.2961.5.camel@hpdv5.satnam> Mime-Version: 1.0 X-Mailer: Evolution 2.24.5 (2.24.5-1.fc10) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2970 Lines: 85 On Sat, 2009-06-27 at 04:31 +0000, tip-bot for Ingo Molnar wrote: > Commit-ID: 0cfb7a13b8e4e0afd4b856156ab16a182de7505b > Gitweb: http://git.kernel.org/tip/0cfb7a13b8e4e0afd4b856156ab16a182de7505b > Author: Ingo Molnar > AuthorDate: Sat, 27 Jun 2009 06:10:30 +0200 > Committer: Ingo Molnar > CommitDate: Sat, 27 Jun 2009 06:11:24 +0200 > > perf stat: Add -n/--null option to run without counters > > Allow a no-counters run. This can be useful to measure just > elapsed wall-clock time - or to assess the raw overhead of perf > stat itself, without running any counters. > Why it better then $ time Any way this patch is broken. Why you are allocating : memcpy(attrs, default_attrs, sizeof(attrs)); when null_run is set. To get better picture and solution, Please check [PATCH] perf stat: fix default attrs and nr_counters which I send in "Re: [PATCH -tip] perf_counter tools: add support to set of multiple events in one short" send on Fri, 26 Jun 2009 18:08:40 +0530 Thanks, -- JSR > Cc: Peter Zijlstra > Cc: Mike Galbraith > Cc: Paul Mackerras > Cc: Arnaldo Carvalho de Melo > LKML-Reference: > Signed-off-by: Ingo Molnar > > > --- > tools/perf/builtin-stat.c | 5 ++++- > 1 files changed, 4 insertions(+), 1 deletions(-) > > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c > index 8420ec5..cdcd058 100644 > --- a/tools/perf/builtin-stat.c > +++ b/tools/perf/builtin-stat.c > @@ -70,6 +70,7 @@ static int run_count = 1; > static int inherit = 1; > static int scale = 1; > static int target_pid = -1; > +static int null_run = 0; > > static int fd[MAX_NR_CPUS][MAX_COUNTERS]; > > @@ -461,6 +462,8 @@ static const struct option options[] = { > "be more verbose (show counter open errors, etc)"), > OPT_INTEGER('r', "repeat", &run_count, > "repeat command and print average + stddev (max: 100)"), > + OPT_BOOLEAN('n', "null", &null_run, > + "null run - dont start any counters"), > OPT_END() > }; > > @@ -476,7 +479,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix) > if (run_count <= 0 || run_count > MAX_RUN) > usage_with_options(stat_usage, options); > > - if (!nr_counters) > + if (!null_run && !nr_counters) > nr_counters = 8; > > nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); > -- > 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/ -- 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/