From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262270AbVGMXLJ (ORCPT ); Wed, 13 Jul 2005 19:11:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262471AbVGMXKz (ORCPT ); Wed, 13 Jul 2005 19:10:55 -0400 Received: from gateway-1237.mvista.com ([12.44.186.158]:56314 "EHLO av.mvista.com") by vger.kernel.org with ESMTP id S262270AbVGMXJe (ORCPT ); Wed, 13 Jul 2005 19:09:34 -0400 Message-ID: <42D59EB5.6040200@mvista.com> Date: Wed, 13 Jul 2005 16:07:33 -0700 From: George Anzinger Reply-To: george@mvista.com Organization: MontaVista Software User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.6) Gecko/20050323 Fedora/1.7.6-1.3.2 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Lee Revell CC: Chris Wedgwood , Andrew Morton , "Brown, Len" , dtor_core@ameritech.net, torvalds@osdl.org, 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 Subject: Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt References: <42D3E852.5060704@mvista.com> <20050712162740.GA8938@ucw.cz> <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> <1121289881.4435.102.camel@mindpipe> In-Reply-To: <1121289881.4435.102.camel@mindpipe> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Lee Revell wrote: > On Wed, 2005-07-13 at 14:16 -0700, Chris Wedgwood wrote: > >>Both can be detected from you .config and we could see HZ as needed >>there and everyone else could avoid this surely? > > Does anyone object to setting HZ at boot? I suspect nothing else will > make everyone happy. > This will really mess up the jiffie_to_* and *_to_jiffie conversions. They rely in a rather large way on the complier doing all the heavy lifting. If HZ is a variable we introduce a LOT of runtime overhead here. (Try make kernel/itimer.i and look for jiffies_to_t* and friends.) -- George Anzinger george@mvista.com HRT (High-res-timers): http://sourceforge.net/projects/high-res-timers/