Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932591AbVISTRE (ORCPT ); Mon, 19 Sep 2005 15:17:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932594AbVISTRE (ORCPT ); Mon, 19 Sep 2005 15:17:04 -0400 Received: from e34.co.us.ibm.com ([32.97.110.152]:22667 "EHLO e34.co.us.ibm.com") by vger.kernel.org with ESMTP id S932591AbVISTRD (ORCPT ); Mon, 19 Sep 2005 15:17:03 -0400 Subject: [PATCH] x86-64: Fix bad assumption that dualcore cpus have synced TSCs From: john stultz To: Andrew Morton Cc: lkml , Andi Kleen Content-Type: text/plain Date: Mon, 19 Sep 2005 12:16:43 -0700 Message-Id: <1127157404.3455.209.camel@cog.beaverton.ibm.com> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1120 Lines: 34 Andrew, This patch should resolve the issue seen in bugme bug #5105, where it is assumed that dualcore x86_64 systems have synced TSCs. This is not the case, and alternate timesources should be used instead. For more details, see: http://bugzilla.kernel.org/show_bug.cgi?id=5105 Please consider for inclusion in your tree. thanks -john diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c --- a/arch/x86_64/kernel/time.c +++ b/arch/x86_64/kernel/time.c @@ -959,9 +959,6 @@ static __init int unsynchronized_tsc(voi are handled in the OEM check above. */ if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) return 0; - /* All in a single socket - should be synchronized */ - if (cpus_weight(cpu_core_map[0]) == num_online_cpus()) - return 0; #endif /* Assume multi socket systems are not synchronized */ return num_online_cpus() > 1; - 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/