From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753123AbZHXTHL (ORCPT ); Mon, 24 Aug 2009 15:07:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752893AbZHXTHJ (ORCPT ); Mon, 24 Aug 2009 15:07:09 -0400 Received: from byss.tchmachines.com ([208.76.80.75]:54300 "EHLO byss.tchmachines.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751724AbZHXTHI (ORCPT ); Mon, 24 Aug 2009 15:07:08 -0400 X-Greylist: delayed 2405 seconds by postgrey-1.27 at vger.kernel.org; Mon, 24 Aug 2009 15:07:07 EDT Date: Mon, 24 Aug 2009 11:26:59 -0700 From: Ravikiran G Thirumalai To: Ingo Molnar Cc: Yinghai Lu , torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, shai@scalex86.org Subject: [patch] x86: 2.6.31-rc7 crash due to buggy flat_phys_pkg_id Message-ID: <20090824182659.GA6842@localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.15+20070412 (2007-04-11) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - byss.tchmachines.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - scalex86.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.31-rc7 does not boot on vSMPowered systems. The sched domains seem to build incorrectly with error messages of the sort: [ 8.501108] CPU31: Thermal monitoring enabled (TM1) [ 8.501127] CPU 31 MCA banks SHD:2 SHD:3 SHD:5 SHD:6 SHD:8 [ 8.650254] CPU31: Intel(R) Xeon(R) CPU E5540 @ 2.53GHz stepping 04 [ 8.710324] Brought up 32 CPUs [ 8.713916] Total of 32 processors activated (162314.96 BogoMIPS). [ 8.721489] ERROR: parent span is not a superset of domain->span [ 8.727686] ERROR: domain->groups does not contain CPU0 [ 8.733091] ERROR: groups don't span domain->span [ 8.737975] ERROR: domain->cpu_power not set [ 8.742416] This is followed by oopsen in the scheduler code with NULL pointer deference in find_busiest_group. Git bisection pointed to the following commit: commit 2759c3287de27266e06f1f4e82cbd2d65f6a044c x86: don't call read_apic_id if !cpu_has_apic Upon examining the history of the commit, the above commit seems to be a fix for: commit 4797f6b021a3fa399942245d07a1feb30df81bb8 x86: read apic ID in the !acpi_lapic case However, there appears to be bug in the commit 2759c3287de27266e06f1f4e82cbd2d65f6a044c, where flat_phys_pkg_id uses initial apic id instead of hard_smp_processor_id() on SMP machines. http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=2759c3287de27266e06f1f4e82cbd2d65f6a044c This patch fixes the bug and causes vSMPowered systems to boot up correctly, Signed-off-by: Ravikiran Thirumalai Cc: Yinghai Lu Index: linux-2.6.31-rc6/arch/x86/kernel/apic/apic_flat_64.c =================================================================== --- linux-2.6.31-rc6.orig/arch/x86/kernel/apic/apic_flat_64.c 2009-08-21 12:42:16.000000000 -0700 +++ linux-2.6.31-rc6/arch/x86/kernel/apic/apic_flat_64.c 2009-08-21 14:12:21.654837472 -0700 @@ -161,7 +161,8 @@ static int flat_apic_id_registered(void) static int flat_phys_pkg_id(int initial_apic_id, int index_msb) { - return initial_apic_id >> index_msb; + return cpu_has_apic ? hard_smp_processor_id() >> index_msb : + initial_apic_id >> index_msb; } struct apic apic_flat = {