From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756849AbaGQNJv (ORCPT ); Thu, 17 Jul 2014 09:09:51 -0400 Received: from mail.kernel.org ([198.145.19.201]:42187 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755175AbaGQNJt (ORCPT ); Thu, 17 Jul 2014 09:09:49 -0400 Date: Thu, 17 Jul 2014 10:09:43 -0300 From: Arnaldo Carvalho de Melo To: Peter Zijlstra Cc: Namhyung Kim , Ingo Molnar , Paul Mackerras , Namhyung Kim , LKML , Jiri Olsa , Minchan Kim Subject: Re: [PATCH] perf stat: Pass PERF_STAT_RUN environment variable for each run Message-ID: <20140717130943.GA4312@kernel.org> References: <1405585266-28268-1-git-send-email-namhyung@kernel.org> <20140717082613.GF19379@twins.programming.kicks-ass.net> <20140717084011.GG19379@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140717084011.GG19379@twins.programming.kicks-ass.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, Jul 17, 2014 at 10:40:11AM +0200, Peter Zijlstra escreveu: > On Thu, Jul 17, 2014 at 05:31:14PM +0900, Namhyung Kim wrote: > > On Thu, Jul 17, 2014 at 5:26 PM, Peter Zijlstra wrote: > > > On Thu, Jul 17, 2014 at 05:21:06PM +0900, Namhyung Kim wrote: > > >> When perf stat runs multiple times via -r option, it's sometimes > > >> useful for a workload to know which run it executing. So pass new > > >> PERF_STAT_RUN environment variable to the workload for each run > > >> (starting from 1). > > > This seems counter intuitive, runs should be _identical_ otherwise > > > there's no point. That means the workload should very much _not_ know > > > these things. > > But I think it can be useful if a workload wants to save logfiles > > based on the iteration number for example. If it doesn't want, it can > > just ignore. :) > That's the wrong way around. Also, there's --pre and --post hooks to > preserve logfiles if you really have to do that kind of thing. Agreed, one can script this using --pre or --post if needed. - Arnaldo