Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265558AbTFRV6r (ORCPT ); Wed, 18 Jun 2003 17:58:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265560AbTFRV6r (ORCPT ); Wed, 18 Jun 2003 17:58:47 -0400 Received: from palrel10.hp.com ([156.153.255.245]:50906 "EHLO palrel10.hp.com") by vger.kernel.org with ESMTP id S265558AbTFRV6q (ORCPT ); Wed, 18 Jun 2003 17:58:46 -0400 From: David Mosberger MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16112.58330.522570.329438@napali.hpl.hp.com> Date: Wed, 18 Jun 2003 15:12:42 -0700 To: Andi Kleen Cc: David Mosberger , linux-kernel@vger.kernel.org Subject: Re: add /proc/sys/kernel/cache_decay_ticks In-Reply-To: References: <200306182151.h5ILpMcx022062@napali.hpl.hp.com.suse.lists.linux.kernel> X-Mailer: VM 7.07 under Emacs 21.2.1 Reply-To: davidm@hpl.hp.com X-URL: http://www.hpl.hp.com/personal/David_Mosberger/ Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1389 Lines: 30 >>>>> On 19 Jun 2003 00:05:18 +0200, Andi Kleen said: Andi> David Mosberger writes: >> /proc/sys/kernel/cache_decay_ticks allows runtime tuning of the >> scheduler. The earlier patch collided with the C99-ification of >> the file, so here is a retransmit. Andi> Funny, I did a similar patch for 2.4 a short time ago. But I Andi> would suggest one change before you merge that to Andi> mainline. The variable is currently used like this: Andi> #define CAN_MIGRATE_TASK(p,rq,this_cpu) \ ((jiffies - Andi> (p)->last_run > cache_decay_ticks) && \o Andi> Which means 0 means 1 jiffie. For a tunable it would be useful Andi> to be able to turn it off completely, which means the > needs Andi> to be replaced with a >=. Unfortunately this requires changes Andi> in the architectures too to subtract one. But it would make it Andi> more useful. I would do the change before exposing it. I don't see why the two have to be tied together. I agree it would be _nice_, but having /proc/sys/kernel/cache_decay_ticks in it's current form is much better than nothing at all. --david - 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/