From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755354AbZEKTJf (ORCPT ); Mon, 11 May 2009 15:09:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753641AbZEKTJZ (ORCPT ); Mon, 11 May 2009 15:09:25 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:59955 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753208AbZEKTJZ (ORCPT ); Mon, 11 May 2009 15:09:25 -0400 Date: Mon, 11 May 2009 21:09:10 +0200 From: Ingo Molnar To: "H. Peter Anvin" Cc: Jaswinder Singh Rajput , "H. Peter Anvin" , Robert Richter , x86 maintainers , LKML Subject: Re: [PATCH 2/15 -tip] x86: Add cpufeatures for Advanced Power Management Message-ID: <20090511190910.GA28684@elte.hu> References: <1242058494.5139.7.camel@ht.satnam> <1242060119.5139.9.camel@ht.satnam> <1242060207.5139.11.camel@ht.satnam> <4A086AB2.7010309@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4A086AB2.7010309@zytor.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * H. Peter Anvin wrote: > Jaswinder Singh Rajput wrote: >> 1. Add Advanced Power Management (Function 8000_0007h), edx >> 2. unification of X86_FEATURE_CONSTANT_TSC (from intel.c, amd.c to common.c) >> 3. Remove cpu/powerflags.c >> 4. Remove x86_power >> 5. Move 'power management' to flags of /proc/cpuinfo >> >> /proc/cpuinfo (before) >> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge >> mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt >> rdtscp lm 3dnowext 3dnow constant_tsc rep_good nonstop_tsc pni cx16 >> lahf_lm cmp_legacy svm extapic cr8_legacy 3dnowprefetch osvw skinit pname >> .. >> power management: ts ttp tm stc 100mhzsteps hwpstate >> >> /proc/cpuinfo (after) >> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge >> mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt >> rdtscp lm 3dnowext 3dnow rep_good tsc_reliable nonstop_tsc pni cx16 >> lahf_lm cmp_legacy svm extapic cr8_legacy 3dnowprefetch osvw skinit pname >> ts ttp htc stc 100mhzsteps hwpstate constant_tsc >> >> Signed-off-by: Jaswinder Singh Rajput > > NAK in the extreme. > > This is an incompatible change to a userspace visible API. The > fact that power management flags were separate was braindamage in > the first place, of course, but we don't break established > userspace APIs even if they're stupid. Yes, and you pointed it out in an earlier reply. Jaswinder, as hpa said it before, we only ever extend cpuflags (i.e. add new ones mainly, and map new CPUs to the existing flags), but we dont change their semantics. Ingo