Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757270Ab1DHAf4 (ORCPT ); Thu, 7 Apr 2011 20:35:56 -0400 Received: from mga11.intel.com ([192.55.52.93]:36589 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757204Ab1DHAfz (ORCPT ); Thu, 7 Apr 2011 20:35:55 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.63,320,1299484800"; d="scan'208";a="676601233" Subject: Re: [PATCH]sched: convert wall-time to vruntime for check_preempt_tick From: Shaohua Li To: Mike Galbraith Cc: "linux-kernel@vger.kernel.org" , "mingo@elte.hu" , "Yan, Zheng Z" In-Reply-To: <1302183260.8065.9.camel@marge.simson.net> References: <20110407124332.GA31809@sli10-conroe.sh.intel.com> <1302183260.8065.9.camel@marge.simson.net> Content-Type: text/plain; charset="UTF-8" Date: Fri, 08 Apr 2011 08:35:53 +0800 Message-ID: <1302222953.3981.88.camel@sli10-conroe> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 749 Lines: 15 On Thu, 2011-04-07 at 21:34 +0800, Mike Galbraith wrote: > On Thu, 2011-04-07 at 20:43 +0800, Shaohua Li wrote: > > In check_preempt_tick(), delta is vruntime and ideal_runtime is wall runtime. > > Comparing vruntime and ideal_runtime looks buggy. > > Why is that buggy? It's a distance in units ns, ala wakeup_granularity, > a number. This number just happens to be variable. vruntime is scaled wall-time. In all other places we do the scale from my understanding. I'm wondering why not do it here. -- 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/