From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262563AbVGMFiC (ORCPT ); Wed, 13 Jul 2005 01:38:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262588AbVGMFiC (ORCPT ); Wed, 13 Jul 2005 01:38:02 -0400 Received: from mustang.oldcity.dca.net ([216.158.38.3]:39377 "HELO mustang.oldcity.dca.net") by vger.kernel.org with SMTP id S262563AbVGMFhz (ORCPT ); Wed, 13 Jul 2005 01:37:55 -0400 Subject: Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt From: Lee Revell To: "Martin J. Bligh" Cc: "Kjetil Svalastog Matheussen " , Chris Friesen , 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: <278570000.1121206956@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> <1121113532.2383.6.camel@mindpipe> <42D2D912.3090505@nortel.com> <1121128260.2632.12.camel@mindpipe> <165840000.1121141256@[10.10.2.4]> <1121141602.2632.31.camel@mindpipe> <188690000.1121142633@[10.10.2.4]> <1121201925.10580.24.camel@mindpipe> <278570000.1121206956@flay> Content-Type: text/plain Date: Wed, 13 Jul 2005 01:37:53 -0400 Message-Id: <1121233074.4435.8.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 Tue, 2005-07-12 at 15:22 -0700, Martin J. Bligh wrote: > > --On Tuesday, July 12, 2005 16:58:44 -0400 Lee Revell wrote: > > > On Mon, 2005-07-11 at 21:30 -0700, Martin J. Bligh wrote: > >> Some sort of comprimise has to be struck for now, until we get sub-HZ > >> timers. I'd prefer 100, personally (I had that set as default in my tree > >> for a long time). Some people would prefer 1000 or even more, maybe. > >> 250/300 seems like a reasonable comprimise to me. Exactly what problems > >> *does* it cause (in visible effect, not "timers are less granular"). > >> Jittery audio/video? How much worse is it? > > > > OK, here's a real world example, taken straight from the linux-audio-dev > > list today. > > OK, what level causes Midi stuttering to stop then, under some fairly > reasonable load? Of course ... if we set HZ to 100000, we'll get higher > res still ... the question is how high it *needs* to be ;-) I don't remember the details, but they can be found in the list archives. I only remember that 100HZ is not good enough and 1000HZ is OK. Anyway it looks like this is a done deal. If it breaks a lot of apps then we'll have to deal with it. Lee