Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934141AbYBVMZ3 (ORCPT ); Fri, 22 Feb 2008 07:25:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756739AbYBVMZV (ORCPT ); Fri, 22 Feb 2008 07:25:21 -0500 Received: from mail.suse.de ([195.135.220.2]:38967 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755215AbYBVMZT (ORCPT ); Fri, 22 Feb 2008 07:25:19 -0500 To: Yinghai Lu Cc: Ingo Molnar , Andrew Morton , Linux Kernel Mailing List Subject: Re: [PATCH] x86_64: make amd quad core 8 socket system not be clustered_box From: Andi Kleen References: <200802210258.45011.yinghai.lu@sun.com> Date: Fri, 22 Feb 2008 13:25:18 +0100 In-Reply-To: <200802210258.45011.yinghai.lu@sun.com> (Yinghai Lu's message of "Thu\, 21 Feb 2008 02\:58\:44 -0800") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1249 Lines: 33 Yinghai Lu writes: > quad core 8 socket system will have apic id lifting.the apic id range could > be [4, 0x23]. or [8, 0x27]. apic_is_clustered_box will think that need to three clusters > and that is large than 2. So it is treated as clustered_box. > > and will get > > Marking TSC unstable due to TSCs unsynchronized > > even the CPUs have X86_FEATURE_CONSTANT_TSC set. > > this patch offset back the apic before get apic clusterid. > > or use dmi to get apic_is_clustered? The clustered check is for Summit and es7000 systems On 64bit systems it might be actually possible to trigger this based on SLIT instead. But you'll need to check with the IBM Summit/Unisys es7000 developers if that works or not If you don't want to do that the safer way would be probably the check if there are holes between the CPUs APIC numbers. If yes then it's likely clustered mode. I think that would be better than to disable it unconditionally for apic lifting like your patches does. -Andi -- 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/