From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755788Ab2FFOOg (ORCPT ); Wed, 6 Jun 2012 10:14:36 -0400 Received: from merlin.infradead.org ([205.233.59.134]:47785 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755693Ab2FFOOf convert rfc822-to-8bit (ORCPT ); Wed, 6 Jun 2012 10:14:35 -0400 Message-ID: <1338992061.2749.111.camel@twins> Subject: Re: [PATCH 1/5] perf, x86: Don't assume the alternative cycles encoding is architectural From: Peter Zijlstra To: Andi Kleen Cc: Andi Kleen , linux-kernel@vger.kernel.org, eranian@google.com Date: Wed, 06 Jun 2012 16:14:21 +0200 In-Reply-To: <20120606141247.GD28225@tassilo.jf.intel.com> References: <1338944211-28275-1-git-send-email-andi@firstfloor.org> <1338979188.2749.92.camel@twins> <20120606141247.GD28225@tassilo.jf.intel.com> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2012-06-06 at 07:12 -0700, Andi Kleen wrote: > On Wed, Jun 06, 2012 at 12:39:48PM +0200, Peter Zijlstra wrote: > > On Tue, 2012-06-05 at 17:56 -0700, Andi Kleen wrote: > > > From: Andi Kleen > > > > > > cycles:p uses an special cycles encoding by default. However that is not > > > architectural, so it can only be used when the CPU is known > > > (it already caused problems on Sandy Bridge). It may or may not work > > > on future CPUs. > > > > > > So make it opt-in only. Right now I enabled it on Core2, Nehalem, Westmere > > > and not on Sandy-Bridge or Atom. > > > > No. > > What do you mean? Are you claiming it's architectural? I mean this patch is shite. You don't disable it because it doesn't work some place, you fix it. But don't bother, its already done.