From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755566AbaCYVBW (ORCPT ); Tue, 25 Mar 2014 17:01:22 -0400 Received: from mga11.intel.com ([192.55.52.93]:40489 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754648AbaCYVBU (ORCPT ); Tue, 25 Mar 2014 17:01:20 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,730,1389772800"; d="scan'208";a="499415166" Date: Tue, 25 Mar 2014 14:01:09 -0700 From: Andi Kleen To: Stephane Eranian Cc: Andi Kleen , Arnaldo Carvalho de Melo , Ingo Molnar , LKML , Peter Zijlstra , Namhyung Kim , Jiri Olsa Subject: Re: [PATCH] tools, perf: Allow the user to disable time stamps Message-ID: <20140325210109.GH15074@tassilo.jf.intel.com> References: <1395780272-27106-1-git-send-email-andi@firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > Timestamp are useful to order samples during reporting. > How do you do with it if you monitor multi-threaded (multi-cpu) > workloads. This is only good for single thread or single CPU > measurements. Or am I missing something? For a perf report order doesn't matter (except against mmaps) The CPUs are still separated of course You're right for some special analysis it matters, that is why it is only an option. But for the standard "only care about perf report and don't care about about program startup" case it's a nice saving. -Andi