From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760271AbZFJQkL (ORCPT ); Wed, 10 Jun 2009 12:40:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754198AbZFJQj7 (ORCPT ); Wed, 10 Jun 2009 12:39:59 -0400 Received: from hera.kernel.org ([140.211.167.34]:49509 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753162AbZFJQj6 (ORCPT ); Wed, 10 Jun 2009 12:39:58 -0400 Subject: Re: [PATCH -tip] x86: cpu/proc.c adding extended_cpuid_level for /proc/cpuinfo From: Jaswinder Singh Rajput To: "H. Peter Anvin" Cc: Andrew Morton , Ingo Molnar , x86 maintainers , LKML In-Reply-To: <1244262225.2449.22.camel@ht.satnam> References: <1242112482.3283.1.camel@localhost.localdomain> <20090512232122.61f2d7c5.akpm@linux-foundation.org> <1244227115.2507.3.camel@ht.satnam> <4A29862D.6030601@zytor.com> <1244262225.2449.22.camel@ht.satnam> Content-Type: text/plain Date: Wed, 10 Jun 2009 22:10:44 +0530 Message-Id: <1244652044.3295.10.camel@ht.satnam> Mime-Version: 1.0 X-Mailer: Evolution 2.24.5 (2.24.5-1.fc10) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Peter, On Sat, 2009-06-06 at 09:53 +0530, Jaswinder Singh Rajput wrote: > On Fri, 2009-06-05 at 13:55 -0700, H. Peter Anvin wrote: > > Jaswinder Singh Rajput wrote: > > > Hello Andrew, > > > > > > On Tue, 2009-05-12 at 23:21 -0700, Andrew Morton wrote: > > >> On Tue, 12 May 2009 12:44:42 +0530 Jaswinder Singh Rajput wrote: > > >> > > >>> + "ext cpuid level\t: 0x%x\n" > > >> It's unobvious what "ext" means. External? > > >> > > >> Can we make it "extended cpuid level"? > > > > > > extended cpuid level will look like this : > > > > > > fpu : yes > > > fpu_exception : yes > > > cpuid level : 5 > > > wp : yes > > > extended cpuid level: 0x80000008 > > > flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe constant_tsc pebs bts pni dtes64 monitor ds_cpl cid > > > > > > > The more I'm thinking about this I think it was a mistake to put cpuid > > level: there in the first place, too. My opinion is increasingly to > > leave this to x86info or other user-space tools. > > > > cpuid level is as important as cpu family, model and stepping. > > For Intel, in some cases cpuid level is more important then cpu family, > model and stepping. Like you cannot tell by looking at cpu family, model > and stepping which model is new and which is old like 05_01 or 06_1A or > 0F_03H ? > > But by looking at cpuid level and extended cpuid level you can tell > which is new and which is old and which supports more features. > > So cpuid level and extended cpuid level is better scale than cpu family, > model and stepping. So I think hiding this valuable information is a > crime. > Highest Value in EAX Intel 64 or IA-32 Processors Basic Information Extended Function Information Earlier Intel486 Processors CPUID Not Implemented CPUID Not Implemented Later Intel486 Processors and 01H Not Implemented Pentium Processors Pentium Pro and Pentium II 02H Not Implemented Processors, Intel Celeron Processors Pentium III Processors 03H Not Implemented Pentium 4 Processors 02H 80000004H Intel Xeon Processors 02H 80000004H Pentium M Processor 02H 80000004H Pentium 4 Processor 05H 80000008H supporting Hyper-Threading Technology Pentium D Processor (8xx) 05H 80000008H Pentium D Processor (9xx) 06H 80000008H Intel Core Duo Processor 0AH 80000008H Intel Core 2 Duo Processor 0AH 80000008H Intel Xeon Processor 3000, 0AH 80000008H 5100, 5200, 5300, 5400 Series Intel Core 2 Duo Processor 0DH 80000008H 8000 Series Intel Xeon Processor 5200, 0AH 80000008H 5400 Series Intel Atom Processor 0AH 80000008H Intel Core i7 Processor 0BH 80000008H cpuid level and extended cpuid level tells the information about Intel processor model. Do you still think it is useless and should not be present in /proc/cpuinfo . Thanks, -- JSR