Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759902AbXIXVc4 (ORCPT ); Mon, 24 Sep 2007 17:32:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756121AbXIXVcn (ORCPT ); Mon, 24 Sep 2007 17:32:43 -0400 Received: from mx1.redhat.com ([66.187.233.31]:35172 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756839AbXIXVcm (ORCPT ); Mon, 24 Sep 2007 17:32:42 -0400 Date: Mon, 24 Sep 2007 17:32:24 -0400 From: Dave Jones To: Matthew Garrett Cc: Andrew Morton , Ingo Oeser , Andi Kleen , Chuck Ebbert , linux-kernel Subject: Re: Why do so many machines need "noapic"? Message-ID: <20070924213224.GI8127@redhat.com> Mail-Followup-To: Dave Jones , Matthew Garrett , Andrew Morton , Ingo Oeser , Andi Kleen , Chuck Ebbert , linux-kernel References: <46DF3BFF.9000809@redhat.com> <20070915003906.5fa6dc0f.akpm@linux-foundation.org> <200709151258.28745.ioe-lkml@rameria.de> <20070915040802.bb3c7093.akpm@linux-foundation.org> <20070915120824.GA21243@srcf.ucam.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070915120824.GA21243@srcf.ucam.org> User-Agent: Mutt/1.5.14 (2007-02-12) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1792 Lines: 45 On Sat, Sep 15, 2007 at 01:08:25PM +0100, Matthew Garrett wrote: > On Sat, Sep 15, 2007 at 04:08:02AM -0700, Andrew Morton wrote: > > > I believe that about two years ago we broke something which caused quite a > > large number of people to need noapic. Is that the case with any of your > > machines? Do you know if they run 2.6.ancient without noapic? > > My recollection is that we shifted from "Enable the apic even if the > BIOS disabled it" to "Only use the apic if the BIOS didn't disable it" > around that time, which meant that distributions could actually turn on > apic-on-up support without breaking everything. That might correspond to > what you're seeing. If memory serves correctly, that was circa 2.6.10, back in these commits.. commit a068ea13d1db406e15c346e93530343f6e70184c Author: Len Brown Date: Sun Oct 10 05:21:08 2004 -0400 [ACPI] If BIOS disabled the LAPIC, believe it by default. "lapic" is available to force enabling the LAPIC in the event you know more than your BIOS vendor. http://bugzilla.kernel.org/show_bug.cgi?id=3238 commit 2fcfece90db9643b6f30a7ad343898a2871e6a81 Author: Len Brown Date: Sat Oct 9 20:12:45 2004 -0400 [ACPI] Don't enable LAPIC when the BIOS disabled it. Doing so apparently breaks every Dell on Earth. http://bugzilla.kernel.org/show_bug.cgi?id=3238 But those changes relate to the local APIC, which 'noapic' shouldn't have any effect on should it ? Dave -- http://www.codemonkey.org.uk - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/