From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756746Ab0LHXUp (ORCPT ); Wed, 8 Dec 2010 18:20:45 -0500 Received: from out01.mta.xmission.com ([166.70.13.231]:51063 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752524Ab0LHXUo (ORCPT ); Wed, 8 Dec 2010 18:20:44 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: Don Zickus Cc: Peter Zijlstra , Vivek Goyal , Yinghai Lu , Ingo Molnar , Jason Wessel , "linux-kernel\@vger.kernel.org" , Haren Myneni References: <20101201195835.GE2511@redhat.com> <1291234036.32004.2008.camel@laptop> <20101202052321.GH18100@redhat.com> <1291275270.4023.20.camel@twins> <20101202161502.GL18100@redhat.com> <1291764620.2032.1293.camel@laptop> <20101208140103.GM21786@redhat.com> <1291818005.28378.38.camel@laptop> <1291820356.28378.83.camel@laptop> <20101208223746.GR21786@redhat.com> Date: Wed, 08 Dec 2010 15:20:37 -0800 In-Reply-To: <20101208223746.GR21786@redhat.com> (Don Zickus's message of "Wed, 8 Dec 2010 17:37:46 -0500") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-XM-SPF: eid=;;;mid=;;;hst=in01.mta.xmission.com;;;ip=98.207.157.188;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1+uZVHmR2EUhRVDumd57aCBCfqLSt/QVxs= X-SA-Exim-Connect-IP: 98.207.157.188 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -3.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa01 1397; Body=1 Fuz1=1 Fuz2=1] * 0.4 UNTRUSTED_Relay Comes from a non-trusted relay X-Spam-DCC: XMission; sa01 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Don Zickus X-Spam-Relay-Country: Subject: Re: perf hw in kexeced kernel broken in tip X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Fri, 06 Aug 2010 16:31:04 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Don Zickus writes: > On Wed, Dec 08, 2010 at 03:59:16PM +0100, Peter Zijlstra wrote: >> On Wed, 2010-12-08 at 15:20 +0100, Peter Zijlstra wrote: >> >> > > I wonder if you should reverse these checks. If the bios has the perf >> > > counter enabled, there might be a high chance that it fails the first >> > > check and never gets to the actually bios checks. >> > >> > Ah, good point. >> >> Something like so.. > > This seems to work correctly on my Nehalem and broken bios machines during > boot and kexec. As expected it fails during kdump. My p4 box failed > during kexec for some reason. But p4 has other issues. Does the kdump kernel still boot? It looks like it should I just want to double check. Eric