From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754110Ab1D1G4G (ORCPT ); Thu, 28 Apr 2011 02:56:06 -0400 Received: from hera.kernel.org ([140.211.167.34]:55654 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752575Ab1D1G4E (ORCPT ); Thu, 28 Apr 2011 02:56:04 -0400 Date: Thu, 28 Apr 2011 06:55:24 GMT From: tip-bot for Ingo Molnar Message-ID: Cc: linux-kernel@vger.kernel.org, acme@redhat.com, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, fweisbec@gmail.com, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, acme@redhat.com, linux-kernel@vger.kernel.org, fweisbec@gmail.com, a.p.zijlstra@chello.nl, tglx@linutronix.de, mingo@elte.hu To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/stat] perf stat: Add --sync/-S option Git-Commit-ID: f9cef0a90c4e7637f1ec98474a1a099aec45eb65 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Thu, 28 Apr 2011 06:55:25 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: f9cef0a90c4e7637f1ec98474a1a099aec45eb65 Gitweb: http://git.kernel.org/tip/f9cef0a90c4e7637f1ec98474a1a099aec45eb65 Author: Ingo Molnar AuthorDate: Thu, 28 Apr 2011 18:17:11 +0200 Committer: Ingo Molnar CommitDate: Thu, 28 Apr 2011 08:39:39 +0200 perf stat: Add --sync/-S option --sync will tell perf stat to run sync() before starting a command. This allows IO-heavy tests to be used with --repeat, without one iteration impacting the other. Elapsed time will stabilize for example: before: 3.971525714 seconds time elapsed ( +- 8.56% ) after: 3.211098537 seconds time elapsed ( +- 1.52% ) So measurements will be more accurate. Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Link: http://lkml.kernel.org/n/tip-7y40wib8n1eqio7hjpn1dsrm@git.kernel.org Signed-off-by: Ingo Molnar --- tools/perf/builtin-stat.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index 003caa8..5658a77 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -128,6 +128,7 @@ static pid_t target_tid = -1; static pid_t child_pid = -1; static bool null_run = false; static bool detailed_run = false; +static bool sync_run = false; static bool big_num = true; static int big_num_opt = -1; static const char *cpu_list; @@ -819,6 +820,8 @@ static const struct option options[] = { "null run - dont start any counters"), OPT_BOOLEAN('d', "detailed", &detailed_run, "detailed run - start a lot of events"), + OPT_BOOLEAN('S', "sync", &sync_run, + "call sync() before starting a run"), OPT_CALLBACK_NOOPT('B', "big-num", NULL, NULL, "print large numbers with thousands\' separators", stat__set_big_num), @@ -944,6 +947,10 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used) for (run_idx = 0; run_idx < run_count; run_idx++) { if (run_count != 1 && verbose) fprintf(stderr, "[ perf stat: executing run #%d ... ]\n", run_idx + 1); + + if (sync_run) + sync(); + status = run_perf_stat(argc, argv); }