Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755924AbYCTHqQ (ORCPT ); Thu, 20 Mar 2008 03:46:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754182AbYCTHpy (ORCPT ); Thu, 20 Mar 2008 03:45:54 -0400 Received: from byss.tchmachines.com ([208.76.80.75]:48094 "EHLO byss.tchmachines.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753646AbYCTHpx (ORCPT ); Thu, 20 Mar 2008 03:45:53 -0400 Date: Thu, 20 Mar 2008 00:45:08 -0700 From: Ravikiran G Thirumalai To: Andrew Morton , Ingo Molnar Cc: linux-kernel@vger.kernel.org, Glauber de Oliveira Costa , Andi Kleen , shai@scalex86.org Subject: [patch 4/4] x86: apic_is_clustered_box to indicate unsynched TSC's on multiboard vSMP systems Message-ID: <20080320074508.GE9414@localdomain> References: <20080320073740.GA9414@localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080320073740.GA9414@localdomain> User-Agent: Mutt/1.5.13 (2006-08-11) 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 Content-Length: 1453 Lines: 36 Indicate TSCs are unreliable as time sources if the platform is a multi chassi ScaleMP vSMPowered machine. Signed-off-by: Ravikiran Thirumalai Index: linux.git.trees/arch/x86/kernel/apic_64.c =================================================================== --- linux.git.trees.orig/arch/x86/kernel/apic_64.c 2008-03-19 20:42:28.187659497 -0700 +++ linux.git.trees/arch/x86/kernel/apic_64.c 2008-03-19 21:24:17.705515003 -0700 @@ -1208,7 +1208,7 @@ __cpuinit int apic_is_clustered_box(void * will be [4, 0x23] or [8, 0x27] could be thought to * vsmp box still need checking... */ - if (!is_vsmp_box() && (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)) + if ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && !is_vsmp_box()) return 0; bios_cpu_apicid = x86_bios_cpu_apicid_early_ptr; @@ -1248,6 +1248,12 @@ __cpuinit int apic_is_clustered_box(void ++zeros; } + /* ScaleMP vSMPowered boxes have one cluster per board and TSCs are + * not guaranteed to be synced between boards + */ + if (is_vsmp_box() && clusters > 1) + return 1; + /* * If clusters > 2, then should be multi-chassis. * May have to revisit this when multi-core + hyperthreaded CPUs come -- 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/