From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262939AbVGNHm4 (ORCPT ); Thu, 14 Jul 2005 03:42:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262943AbVGNHm4 (ORCPT ); Thu, 14 Jul 2005 03:42:56 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:48533 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S262939AbVGNHmz (ORCPT ); Thu, 14 Jul 2005 03:42:55 -0400 Subject: Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt From: Arjan van de Ven To: Linus Torvalds Cc: Lee Revell , dean gaudet , Chris Wedgwood , Andrew Morton , "Brown, Len" , dtor_core@ameritech.net, vojtech@suse.cz, david.lang@digitalinsight.com, davidsen@tmr.com, kernel@kolivas.org, linux-kernel@vger.kernel.org, mbligh@mbligh.org, diegocg@gmail.com, azarah@nosferatu.za.org, christoph@lameter.com In-Reply-To: References: <42D540C2.9060201@tmr.com> <20050713184227.GB2072@ucw.cz> <1121282025.4435.70.camel@mindpipe> <1121286258.4435.98.camel@mindpipe> <20050713134857.354e697c.akpm@osdl.org> <20050713211650.GA12127@taniwha.stupidest.org> <20050714005106.GA16085@taniwha.stupidest.org> <1121304825.4435.126.camel@mindpipe> Content-Type: text/plain Date: Thu, 14 Jul 2005 09:42:18 +0200 Message-Id: <1121326938.3967.12.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.2.2 (2.2.2-5) Content-Transfer-Encoding: 7bit X-Spam-Score: 2.9 (++) X-Spam-Report: SpamAssassin version 3.0.4 on pentafluge.infradead.org summary: Content analysis details: (2.9 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.1 RCVD_IN_SORBS_DUL RBL: SORBS: sent directly from dynamic IP address [80.57.133.107 listed in dnsbl.sorbs.net] 2.8 RCVD_IN_DSBL RBL: Received via a relay in list.dsbl.org [] X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > IOW, nothing ever sees any "variable frequency", and there's never any > question about what the timer tick is: the timer tick is 2kHz as far as > everybody is concerned. It's just that the ticks sometimes come in > "bunches of 20". btw we can hide all of this a lot nicer from just about the entire kernel by reducing the usage of both HZ and jiffies in drivers/non platform code. That isn't hard; msleep() is a good step forward there already; the next step is a nicer api for add_timer/mod_timer that is both relative and in miliseconds; with those 2 the majority of code that has "knowledge" about this shrinks to near zero. Once we have that the actual implementation of this in the background matters a whole lot less.