From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755516Ab2HPNsi (ORCPT ); Thu, 16 Aug 2012 09:48:38 -0400 Received: from mail.skyhub.de ([78.46.96.112]:50212 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752367Ab2HPNsg (ORCPT ); Thu, 16 Aug 2012 09:48:36 -0400 Date: Thu, 16 Aug 2012 15:48:34 +0200 From: Borislav Petkov To: Tomas Racek Cc: "H. Peter Anvin" , Alan Cox , linux-kernel@vger.kernel.org, qemu-devel@nongnu.org Subject: Re: x86, nops settings result in kernel crash Message-ID: <20120816134834.GA11974@x1.osrc.amd.com> Mail-Followup-To: Borislav Petkov , Tomas Racek , "H. Peter Anvin" , Alan Cox , linux-kernel@vger.kernel.org, qemu-devel@nongnu.org References: <1104118228.1760802.1345121009530.JavaMail.root@redhat.com> <711271179.1776875.1345124112800.JavaMail.root@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <711271179.1776875.1345124112800.JavaMail.root@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 16, 2012 at 09:35:12AM -0400, Tomas Racek wrote: > Hi, > > I am writing a file system test which I execute in qemu with kernel compiled from latest git sources and running it causes this error: > > https://bugzilla.kernel.org/show_bug.cgi?id=45971 > > It works with v3.5, so I ran git bisect which pointed me to: > > d6250a3f12edb3a86db9598ffeca3de8b4a219e9 x86, nops: Missing break resulting in incorrect selection on Intel > > To be quite honest, I don't understand this stuff much but I tried to do some debugging and I figured out (I hope) that the crash is caused by setting ideal_nops to p6_nops (k8_nops was used before the break statement was added). Maybe I overlooked it or maybe it was implied but did you try reverting the patch and rerunning your test? Does it work ok then? Thanks. -- Regards/Gruss, Boris.