From owner-cvs-all@FreeBSD.ORG Wed Mar 2 14:24:38 2005 Return-Path: Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id DE45816A4DE for ; Wed, 2 Mar 2005 14:24:36 +0000 (GMT) Received: from mail24.sea5.speakeasy.net (mail24.sea5.speakeasy.net [69.17.117.26]) by mx1.FreeBSD.org (Postfix) with ESMTP id E709043D55 for ; Wed, 2 Mar 2005 14:24:35 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: (qmail 29258 invoked from network); 2 Mar 2005 14:24:35 -0000 Received: from server.baldwin.cx ([216.27.160.63]) (envelope-sender )AES256-SHA encrypted SMTP for ; 2 Mar 2005 14:24:35 -0000 Received: from [10.50.40.202] (gw1.twc.weather.com [216.133.140.1]) (authenticated bits=0) by server.baldwin.cx (8.13.1/8.13.1) with ESMTP id j22EONKt081247; Wed, 2 Mar 2005 09:24:27 -0500 (EST) (envelope-from jhb@FreeBSD.org) From: John Baldwin To: src-committers@FreeBSD.org Date: Wed, 2 Mar 2005 09:25:49 -0500 User-Agent: KMail/1.6.2 References: <200503021417.j22EHhjH076833@repoman.freebsd.org> In-Reply-To: <200503021417.j22EHhjH076833@repoman.freebsd.org> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200503020925.49715.jhb@FreeBSD.org> X-Spam-Status: No, score=-102.8 required=4.2 tests=ALL_TRUSTED, USER_IN_WHITELIST autolearn=failed version=3.0.2 X-Spam-Checker-Version: SpamAssassin 3.0.2 (2004-11-16) on server.baldwin.cx cc: cvs-src@FreeBSD.org cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/i386/i386 local_apic.c X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Mar 2005 14:24:38 -0000 On Wednesday 02 March 2005 09:17 am, John Baldwin wrote: > jhb 2005-03-02 14:17:43 UTC > > FreeBSD src repository > > Modified files: > sys/i386/i386 local_apic.c > Log: > Tweak the lapic timer code to get the performance closer to the pre-lapic > timer case: > - Remove the virtual fooclock interrupt counters as they have served > their purpose. > - Adjust the dividers for the different clock such that profhz is now a > multiple of stathz as in the non-lapic case, and the timer now runs at > hz * 2 rather than hz * 3. With the new divisors, the default clock > rates are: > > kern.clockrate: { hz = 1000, tick = 1000, profhz = 666, stathz = 133 } With these changes and the 8254 interrupt turned off completely, I actually seem to get slightly better performance than pre-lapic timer, though ministat says that pre-lapic timer, the code with this change, and this change + 8254 interrupt are all relatively the same with 95% confidence. Before this change I was seeing about a 0.3% performance regression with lapic timer with 95% confidence. Also, it now should be obvious that profiling is patently evil. :) -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org