From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261241AbVGMQuH (ORCPT ); Wed, 13 Jul 2005 12:50:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261223AbVGMQsP (ORCPT ); Wed, 13 Jul 2005 12:48:15 -0400 Received: from mustang.oldcity.dca.net ([216.158.38.3]:59310 "HELO mustang.oldcity.dca.net") by vger.kernel.org with SMTP id S261250AbVGMQrP (ORCPT ); Wed, 13 Jul 2005 12:47:15 -0400 Subject: Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt From: Lee Revell To: Bill Davidsen Cc: George Anzinger , "Theodore Ts'o" , Andrew Morton , arjan@infradead.org, azarah@nosferatu.za.org, cw@f00f.org, Linux Kernel Mailing List , torvalds@osdl.org, christoph@lameter.org In-Reply-To: <42D53A71.8030901@tmr.com> 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> <1120933916.3176.57.camel@laptopd505.fenrus.org> <1120934163.6488.72.camel@mindpipe> <20050709121212.7539a048.akpm@osdl.org> <1120936561.6488.84.camel@mindpipe> <1121088186.7407.61.camel@localhost.localdomain> <20050711140510.GB14529@thunk.org> <42D53A71.8030901@tmr.com> Content-Type: text/plain Date: Wed, 13 Jul 2005 12:47:12 -0400 Message-Id: <1121273233.4435.32.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 Wed, 2005-07-13 at 11:59 -0400, Bill Davidsen wrote: > Theodore Ts'o wrote: > > The real answer here is for the tickless patches to cleaned up to the > > point where they can be merged, and then we won't waste battery power > > entering the timer interrupt in the first place. :-) > > And that does seem to be the long term solution. Most (not all) modern > hardware has a readable timer as accurate as the tick, so doing a timer > to clock conversion as needed would be possible. > > Unfortunately the interest in tickless operation seems to be mostly in > the power saving possibilities of laptops. If you could make it part of > some really sexy high interest area, like real time premption, it might > get done sooner ;-) > Actually, there is quite a bit of interest already in the same circles that are using RT preempt. "How do I get a timer with better than 1ms resolution" is an FAQ on linux-audio-dev, and once you have dynamic tick the next logical step is high res timers. Currently we refer these users to George's site. I suspect the only reason there has not been more interest is that not many users are up to integrating the HRT and the RT preempt patch. Lee