Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756682AbYGYNkh (ORCPT ); Fri, 25 Jul 2008 09:40:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751833AbYGYNk2 (ORCPT ); Fri, 25 Jul 2008 09:40:28 -0400 Received: from dgate20.fujitsu-siemens.com ([80.70.172.51]:35015 "EHLO dgate20.fujitsu-siemens.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752537AbYGYNk2 (ORCPT ); Fri, 25 Jul 2008 09:40:28 -0400 DomainKey-Signature: s=s768; d=fujitsu-siemens.com; c=nofws; q=dns; h=X-SBRSScore:X-IronPort-AV:Received:X-IronPort-AV: Received:Received:Message-ID:Date:From:Organization: User-Agent:MIME-Version:To:CC:Subject:References: In-Reply-To:Content-Type:Content-Transfer-Encoding; b=aXPKCZN8dY5uXpIdAMlTzK/YWrslA8Im6wTicv09QZItByYEJXwb3Tjs gnPLXEUwrO7bWhd7XuWpkgvRcdn7VBTHm17vrO2/N9ZcfDs31bvtVPioq xnHRapFOmXvtn+A; X-SBRSScore: None X-IronPort-AV: E=Sophos;i="4.31,252,1215381600"; d="scan'208";a="21222489" X-IronPort-AV: E=Sophos;i="4.31,252,1215381600"; d="scan'208";a="36376271" Message-ID: <4889D767.5050709@fujitsu-siemens.com> Date: Fri, 25 Jul 2008 15:38:47 +0200 From: Martin Wilck Organization: Fujitsu Siemens Computers User-Agent: Thunderbird 2.0.0.15pre (X11/20080508) MIME-Version: 1.0 To: Cyrill Gorcunov CC: Thomas Gleixner , "linux-kernel@vger.kernel.org" , "H. Peter Anvin" , "Wichert, Gerhard" , "Maciej W. Rozycki" Subject: Re: [PATCH] x86 (64): make calibrate_APIC_clock() SMI-safe (take 2) References: <20080724111631.GA3432@lenovo> <48886E6D.1030005@fujitsu-siemens.com> <20080724120512.GA21804@lenovo> <488889B6.9070707@fujitsu-siemens.com> <20080724143151.GA32422@lenovo> <20080724150116.GC32422@lenovo> <48889C14.4070408@fujitsu-siemens.com> <4889968E.6020000@fujitsu-siemens.com> <20080725100844.GA16698@lenovo> <4889C723.7050402@fujitsu-siemens.com> <20080725125950.GA28466@lenovo> In-Reply-To: <20080725125950.GA28466@lenovo> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1200 Lines: 35 I wrote: > I have to say that my simplified patch failed to do the calibration > correctly on our test system (the original patch worked well). Please > stay tuned, we are investigating this currently. Please forget that. It was observed on an old "enterprise" kernel with which we are currently testing the backported patch with, and it was due to the fact that the initial counter value on that kernel was divided by APIC_DIVISOR (=16). The resulting initial counter value was too low in a "SMI flood" case, the counter could overlap. APIC_DIVISOR is no longer used in the current kernel. Martin -- Martin Wilck PRIMERGY System Software Engineer FSC IP ESP DEV 6 Fujitsu Siemens Computers GmbH Heinz-Nixdorf-Ring 1 33106 Paderborn Germany Tel: ++49 5251 8 15113 Fax: ++49 5251 8 20209 Email: mailto:martin.wilck@fujitsu-siemens.com Internet: http://www.fujitsu-siemens.com Company Details: http://www.fujitsu-siemens.com/imprint.html -- 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/