From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753962AbZHXXzh (ORCPT ); Mon, 24 Aug 2009 19:55:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753858AbZHXXzf (ORCPT ); Mon, 24 Aug 2009 19:55:35 -0400 Received: from hera.kernel.org ([140.211.167.34]:33703 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753825AbZHXXzf (ORCPT ); Mon, 24 Aug 2009 19:55:35 -0400 Message-ID: <4A932809.1000103@kernel.org> Date: Mon, 24 Aug 2009 16:53:45 -0700 From: Yinghai Lu User-Agent: Thunderbird 2.0.0.22 (X11/20090605) MIME-Version: 1.0 To: Ravikiran G Thirumalai CC: Ingo Molnar , torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, shai@scalex86.org Subject: Re: [patch] x86: 2.6.31-rc7 crash due to buggy flat_phys_pkg_id References: <20090824182659.GA6842@localdomain> In-Reply-To: <20090824182659.GA6842@localdomain> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ravikiran G Thirumalai wrote: > 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; > } it seems we should use initial apic id here. can you check which calling for vsmp cause the problem? arch/x86/kernel/cpu/addon_cpuid_features.c: c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, ht_mask_width) arch/x86/kernel/cpu/addon_cpuid_features.c: c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, core_plus_mask_width ); arch/x86/kernel/cpu/addon_cpuid_features.c: c->apicid = apic->phys_pkg_id(c->initial_apicid, 0); arch/x86/kernel/cpu/common.c: c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, index_msb); arch/x86/kernel/cpu/common.c: c->cpu_core_id = apic->phys_pkg_id(c->initial_apicid, index_msb) & arch/x86/kernel/cpu/common.c: c->apicid = apic->phys_pkg_id(c->initial_apicid, 0); arch/x86/kernel/cpu/common.c: c->apicid = apic->phys_pkg_id(c->initial_apicid, 0); YH