Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761286AbXEOA5z (ORCPT ); Mon, 14 May 2007 20:57:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757423AbXEOA5t (ORCPT ); Mon, 14 May 2007 20:57:49 -0400 Received: from dodo.cs.umass.edu ([128.119.242.12]:47643 "EHLO dodo.cs.umass.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755805AbXEOA5t (ORCPT ); Mon, 14 May 2007 20:57:49 -0400 Message-ID: <46490573.7030101@cs.umass.edu> Date: Mon, 14 May 2007 20:57:23 -0400 From: Ting Yang Reply-To: tingy@cs.umass.edu Organization: ALI Lab, CS Dept, UMASS User-Agent: Thunderbird 2.0.0.0 (Windows/20070326) MIME-Version: 1.0 To: tingy@cs.umass.edu CC: Ingo Molnar , William Lee Irwin III , Srivatsa Vaddagiri , efault@gmx.de, linux-kernel@vger.kernel.org Subject: Re: fair clock use in CFS References: <20070514083358.GA29775@in.ibm.com> <20070514102929.GL31925@holomorphy.com> <20070514103120.GA23766@elte.hu> <20070514110500.GV19966@holomorphy.com> <20070514115049.GA28721@elte.hu> <4648D381.6040808@cs.umass.edu> In-Reply-To: <4648D381.6040808@cs.umass.edu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 938 Lines: 30 > > > It is possible to do something like this in check_preemption ? > > delta = curr->fair_key - first->fair_key; > > if (delta > ??? [scale it as you wish] || > (curr->key > first->key) && (curr->wait_runtime > ??? > [simple funtion of curr->weight]) ) > preempt Forgive me, there is typo in the above check. It should be "less than" since we are controlling negative lags. (curr->key > first->key) && (curr->wait_runtime < ??? [simple funtion of curr->weight]) ) > > A limit control on wait_runtime may prevent a high weight task from > running for too long, so that others get executed a little earlier. > Just a thought :-) > > Ting - 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/