From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755122AbZAKCrO (ORCPT ); Sat, 10 Jan 2009 21:47:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751567AbZAKCq6 (ORCPT ); Sat, 10 Jan 2009 21:46:58 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:35851 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751265AbZAKCq5 (ORCPT ); Sat, 10 Jan 2009 21:46:57 -0500 Date: Sun, 11 Jan 2009 03:46:42 +0100 From: Ingo Molnar To: Jan Beulich Cc: tglx@linutronix.de, hpa@zytor.com, linux-kernel@vger.kernel.org Subject: Re: x86: meaning of nolapic command line option Message-ID: <20090111024642.GA7077@elte.hu> References: <496790D1.76E4.0078.0@novell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <496790D1.76E4.0078.0@novell.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Jan Beulich wrote: > Shouldn't that option imply that all APIC related activity, including > that relating to IO-APICs or PCI MSI, should be circumvented? I'm > finding that MSI must be disabled separately, and while most of the > IO-APIC stuff is indeed not happening, acpi_get_override_irq() only > checks skip_ioapic_setup, but that doesn't normally set without the > noapic command line option. > > Is there any reason pci_no_msi() and disable_ioapic_setup() shouldn't be > called when !cpu_has_apic at the end of identify_cpu()? Yes, both depend on a lapic and they might limp on with whatever the BIOS gave us, you are right that it should be disabled explicitly. Mind sending a patch? Ingo