Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760621AbZGIMiP (ORCPT ); Thu, 9 Jul 2009 08:38:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759854AbZGIMiA (ORCPT ); Thu, 9 Jul 2009 08:38:00 -0400 Received: from one.firstfloor.org ([213.235.205.2]:47268 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757248AbZGIMh7 (ORCPT ); Thu, 9 Jul 2009 08:37:59 -0400 To: Artem Bityutskiy Cc: Al Viro , Jens Axboe , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 00/18] periodic write-back timer optimization From: Andi Kleen References: <20090709084822.12122.79749.sendpatchset@localhost.localdomain> Date: Thu, 09 Jul 2009 14:37:57 +0200 In-Reply-To: <20090709084822.12122.79749.sendpatchset@localhost.localdomain> (Artem Bityutskiy's message of "Thu, 09 Jul 2009 11:48:22 +0300") Message-ID: <871voq6nh6.fsf@basil.nowhere.org> User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/22.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 831 Lines: 24 Artem Bityutskiy writes: > > The patches attempt to optimize the periodic write-back and stop it when > there are no dirty data. IOW, we do not want the thread to wake up every > 5 seconds (by default), find there is nothing to do, and so on. Is waking up every 5 seconds really a problem? The normal rule of thumb is iirc that longer sleep times than a few hundred ms give dimishing returns in terms of power saving. A simple way might be simple to batch the timer better with other timers. -Andi -- ak@linux.intel.com -- Speaking for myself only. -- 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/