From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261938AbVGKU2P (ORCPT ); Mon, 11 Jul 2005 16:28:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262570AbVGKU1d (ORCPT ); Mon, 11 Jul 2005 16:27:33 -0400 Received: from viper.oldcity.dca.net ([216.158.38.4]:17860 "HELO viper.oldcity.dca.net") by vger.kernel.org with SMTP id S262600AbVGKUZe (ORCPT ); Mon, 11 Jul 2005 16:25:34 -0400 Subject: Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt From: Lee Revell To: "Martin J. Bligh" Cc: Diego Calleja , azarah@nosferatu.za.org, akpm@osdl.org, cw@f00f.org, linux-kernel@vger.kernel.org, torvalds@osdl.org, christoph@lameter.org In-Reply-To: <176640000.1121107087@flay> References: <200506231828.j5NISlCe020350@hera.kernel.org> <20050708214908.GA31225@taniwha.stupidest.org> <20050708145953.0b2d8030.akpm@osdl.org> <1120928891.17184.10.camel@lycan.lan> <1120932991.6488.64.camel@mindpipe> <20050709203920.394e970d.diegocg@gmail.com> <1120934466.6488.77.camel@mindpipe> <176640000.1121107087@flay> Content-Type: text/plain Date: Mon, 11 Jul 2005 16:25:32 -0400 Message-Id: <1121113532.2383.6.camel@mindpipe> Mime-Version: 1.0 X-Mailer: Evolution 2.2.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2005-07-11 at 11:38 -0700, Martin J. Bligh wrote: > That's a very subjective viewpoint. Realize that this is a balancing > act between latency and overhead ... and you're firmly only looking > at one side of the argument, instead of taking a comprimise in the > middle ... > > If I start arguing for 100HZ on the grounds that it's much more efficient, > will that make 250/300 look much better to you? ;-) Mostly my argument is that all technical arguments aside, it's crazy to change this in the middle of a stable kernel series. My other objection is that 90% of the arguments for HZ=250 are based on battery life. But most Linux systems still don't run on batteries, so I object to having to take a performance hit (a latency hit, which is the same as performance for multimedia apps) for their sake. Tickless + sub HZ timers is a win for everyone, the multimedia people get better latency, and the laptop people get to run longer. I guess CONFIG_HZ makes sense if the tickless solutions are not going to be ready anytime soon. But I don't see the problem with leaving the default at 1000HZ and letting the laptop users lower it. Lee