Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752020Ab3FZPuy (ORCPT ); Wed, 26 Jun 2013 11:50:54 -0400 Received: from mail-ea0-f178.google.com ([209.85.215.178]:55889 "EHLO mail-ea0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751581Ab3FZPux (ORCPT ); Wed, 26 Jun 2013 11:50:53 -0400 Date: Wed, 26 Jun 2013 17:50:48 +0200 From: Ingo Molnar To: Peter Zijlstra Cc: Mike Galbraith , Dave Chiluk , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: Scheduler accounting inflated for io bound processes. Message-ID: <20130626155048.GA7399@gmail.com> References: <51C35C05.1070005@canonical.com> <1372176104.7497.86.camel@marge.simpson.net> <1372182534.7497.129.camel@marge.simpson.net> <20130626093713.GA27385@gmail.com> <20130626104243.GE28407@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130626104243.GE28407@twins.programming.kicks-ass.net> 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 Content-Length: 873 Lines: 24 * Peter Zijlstra wrote: > On Wed, Jun 26, 2013 at 11:37:13AM +0200, Ingo Molnar wrote: > > Would be very nice to randomize the sampling rate, by randomizing the > > intervals within a 1% range or so - perf tooling will probably recognize > > the different weights. > > You're suggesting adding noise to the regular kernel tick? No, to the perf interval (which I assumed Mike was using to profile this?) - although slightly randomizing the kernel tick might make sense as well, especially if it's hrtimer driven and reprogrammed anyway. I might have gotten it all wrong though ... Thanks, Ingo -- 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/