Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758055AbXERG1c (ORCPT ); Fri, 18 May 2007 02:27:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756953AbXERG1X (ORCPT ); Fri, 18 May 2007 02:27:23 -0400 Received: from mailer.gwdg.de ([134.76.10.26]:35642 "EHLO mailer.gwdg.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752652AbXERG1W (ORCPT ); Fri, 18 May 2007 02:27:22 -0400 Date: Fri, 18 May 2007 08:24:35 +0200 (MEST) From: Jan Engelhardt To: Simon Arlott cc: Claas Langbehn , LKML , hpa@zytor.com, Andrew Morton Subject: Re: This kernel requires the following features not present on the CPU... (on a VIA C7 CPU) In-Reply-To: <464CB726.6090201@simon.arlott.org.uk> Message-ID: References: <464C4A22.7040709@rootdir.de> <464CB726.6090201@simon.arlott.org.uk> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Spam-Report: Content analysis: 0.0 points, 6.0 required _SUMMARY_ Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1956 Lines: 58 Hi, since VIA seems to be one of the quirkier CPUs... On May 17 2007 21:12, Simon Arlott wrote: > On 17/05/07 13:27, Claas Langbehn wrote: >>> Claas Langbehn wrote: >>>> Would it be possible to override the BIOS settings of cx8 and nx and >>>> activate it with linux anyway? >>>> The CPU supports it and I don't see any reason to disable it. >> >> Yes, that code is already in the git.newsetup tree. > > Is it automatic? I have CONFIG_X86_CMPXCHG=y without cx8 showing in cpuinfo, > and it appears to work fine. > > Will your changes needlessly prevent the kernel running? Would I be right in > thinking that the kernel is successfully using cmpxchg even though it's > considered disabled? I realise people compile kernels for the wrong CPU but > preventing them working when it's been chosen correctly seems wrong. > > processor : 0 > vendor_id : CentaurHauls > cpu family : 6 > model : 10 > model name : VIA Esther processor 1500MHz > stepping : 9 > cpu MHz : 800.000 (cpufreq) > cache size : 128 KB > fdiv_bug : no > hlt_bug : no > f00f_bug : no > coma_bug : no > fpu : yes > fpu_exception : yes > cpuid level : 1 > wp : yes > flags : fpu vme de pse tsc msr pae mce apic sep mtrr pge cmov pat > clflush acpi mmx fxsr sse sse2 tm nx pni est tm2 rng rng_en ace ace_en ace2 > ace2_en phe phe_en pmm pmm_en > bogomips : 1601.18 > clflush size : 64 http://lkml.org/lkml/2007/5/5/134 , shows a Family-6 Model-*9* which *does* have CX8 (with CONFIG_M586=y, CONFIG_X86_CMPXCHG=y, CONFIG_X86_CMPXCHG64=y). Just a hint that you do not inadvertently disable CX there ;-) Jan -- - 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/