From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757274AbZEKJUz (ORCPT ); Mon, 11 May 2009 05:20:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755222AbZEKJUq (ORCPT ); Mon, 11 May 2009 05:20:46 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:43666 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753875AbZEKJUp (ORCPT ); Mon, 11 May 2009 05:20:45 -0400 Date: Mon, 11 May 2009 11:20:26 +0200 From: Ingo Molnar To: Yinghai Lu Cc: Cyrill Gorcunov , Thomas Gleixner , "H. Peter Anvin" , "linux-kernel@vger.kernel.org" , Ed Swierk Subject: Re: [PATCH] x86: read apic id if it is not acpi_lapic -v2 Message-ID: <20090511092026.GA26444@elte.hu> References: <20090430084145.GD21699@elte.hu> <49FBD0A2.4030309@kernel.org> <20090502070254.GA4791@lenovo> <49FC85A9.2070702@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49FC85A9.2070702@kernel.org> 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: 0.0079] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Yinghai Lu wrote: > + new_apicid = read_apic_id(); > + if (boot_cpu_physical_apicid != new_apicid) { > + boot_cpu_physical_apicid = new_apicid; > + apic_version[new_apicid] = > + GET_APIC_VERSION(apic_read(APIC_LVR)); > } _Please_, when we override something as critical as this and change the behavior of Linux (even if it's arguably a fix), we must printk a single line to the syslog so that people know what's going on. You really need to make a conscious mental distinction between 'dangerous' code and harmless changes, and apply a lot more conservative approach when you meet and touch (and introduce ...) dangerous code. Thanks, Ingo