From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754620AbYIHPju (ORCPT ); Mon, 8 Sep 2008 11:39:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753078AbYIHPjl (ORCPT ); Mon, 8 Sep 2008 11:39:41 -0400 Received: from terminus.zytor.com ([198.137.202.10]:38460 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752449AbYIHPjl (ORCPT ); Mon, 8 Sep 2008 11:39:41 -0400 Message-ID: <48C54704.2040101@zytor.com> Date: Mon, 08 Sep 2008 08:38:44 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Ingo Molnar CC: Linus Torvalds , linux@sandersweb.net, linux-kernel@vger.kernel.org, the arch/x86 maintainers , Andi Kleen Subject: Re: [BUG] x86 kenel won't boot under Virtual PC References: <200808311422.12525.linux@sandersweb.net> <200809071922.32974.linux@sandersweb.net> <48C48467.40703@zytor.com> <200809072249.17280.linux@sandersweb.net> <48C4A46B.90705@zytor.com> <20080908152330.GA9784@elte.hu> In-Reply-To: <20080908152330.GA9784@elte.hu> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ingo Molnar wrote: >> >> I thought you agreed that CPU virtualization can be a problem? That >> was the whole excuse for why the dynamic code was changed. Why would >> it not be true for the static code? >> >> The fact is, if you want to run on a Core2 or other modern CPU, then >> "Virtual PC" is apparently buggy in this respect. You worked around it >> for the dynamic choice - but that's totally _pointless_ if you then >> don't want to work around it for the static one. > > yes. X86_P6_NOPS is a totally insignificant optimization and if it makes > _any_ CPU not boot (be that virtual or real), then it's frankly not > worth it. > > David, exactly how does the kernel fail to boot with latest -git? > (v2.6.27-rc5-313-g64f996f or later) Does detect_nopl() run? It really > should, and it should detect the non-working instructions. > It almost certainly never gets as far as detect_nopl(). -hpa