From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933155Ab2HPStM (ORCPT ); Thu, 16 Aug 2012 14:49:12 -0400 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:49460 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932391Ab2HPStJ (ORCPT ); Thu, 16 Aug 2012 14:49:09 -0400 Date: Thu, 16 Aug 2012 19:53:24 +0100 From: Alan Cox To: Tomas Racek Cc: Borislav Petkov , "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: <20120816195324.5356cba0@pyramind.ukuu.org.uk> In-Reply-To: <1898701172.1847948.1345142715802.JavaMail.root@redhat.com> References: <20120816134834.GA11974@x1.osrc.amd.com> <1898701172.1847948.1345142715802.JavaMail.root@redhat.com> X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.8; x86_64-redhat-linux-gnu) Face: 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 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 16 Aug 2012 14:45:15 -0400 (EDT) Tomas Racek wrote: > ----- Original Message ----- > > 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? > > > > Yes, if I remove the break statement (introduced by this commit), it works fine. What version of qemu is this - do we have qemu bug here I wonder. Alan