From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753560Ab2AXLgN (ORCPT ); Tue, 24 Jan 2012 06:36:13 -0500 Received: from bar.sig21.net ([80.81.252.164]:38764 "EHLO bar.sig21.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750885Ab2AXLgM (ORCPT ); Tue, 24 Jan 2012 06:36:12 -0500 Date: Tue, 24 Jan 2012 12:36:08 +0100 From: Johannes Stezenbach To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Subject: linux-3.2.1 + KVM: TSC unstable on Core i5-2400S / H67 Message-ID: <20120124113608.GA16876@sig21.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) X-Spam-21-Score: -2.9 (--) X-Spam-21-Report: No, score=-2.9 required=8.0 tests=ALL_TRUSTED=-1,BAYES_00=-1.9 autolearn=ham Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, I just got the following in dmesg with linux-3.2.1: [23379.612251] usb 2-1.2: new high-speed USB device number 6 using ehci_hcd [ 0.006666] Marking TSC unstable due to KVM discovered backwards TSC [23421.511167] Switching to clocksource hpet The mainboard is an Asus P8H67-V, BIOS 0806 10/26/2011 with Core i5-2400S. The kvm instance was running for a day already, and there was an overnight suspend-to-disk cycle in between, but the above happened ~1 hour after resume. (I don't think the usb message has anything to do with it, it's just the last message before the TSC message.) Hm, checking /var/log/kern.* it seems this also happened with linux-3.1.* without me noticing. Should I be worried? I thought Core-i5 processors have a stable TSC? Johannes