From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 12 Jan 2001 13:26:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 12 Jan 2001 13:26:34 -0500 Received: from penguin.e-mind.com ([195.223.140.120]:37680 "EHLO penguin.e-mind.com") by vger.kernel.org with ESMTP id ; Fri, 12 Jan 2001 13:26:30 -0500 Date: Fri, 12 Jan 2001 19:24:39 +0100 From: Andrea Arcangeli To: Linus Torvalds Cc: Richard A Nelson , "Udo A. Steinberg" , Andi Kleen , Linux Kernel Subject: Re: 2.4.1-pre1 breaks XFree 4.0.2 and "w" Message-ID: <20010112192439.U2766@athlon.random> In-Reply-To: <20010112180556.J2766@athlon.random> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ; from torvalds@transmeta.com on Fri, Jan 12, 2001 at 09:35:14AM -0800 X-GnuPG-Key-URL: http://e-mind.com/~andrea/aa.gnupg.asc X-PGP-Key-URL: http://e-mind.com/~andrea/aa.asc Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 12, 2001 at 09:35:14AM -0800, Linus Torvalds wrote: > > > On Fri, 12 Jan 2001, Andrea Arcangeli wrote: > > > On Fri, Jan 12, 2001 at 11:42:32AM -0500, Richard A Nelson wrote: > > > > > > Its fine either way on current x86 and many other platforms, but falls > > > on its face in the presence of asymetric MP. > > > > Point taken, feel free to have a can_I_use per-cpu instead of global but don't > > overwrite the cpu_has with it. > > Andrea, the whole POINT of "cpu_has_xxx" is for the kernel to test for > features like this. I'm only concerned about the semantics of fxsr and xmm in /proc/cpuinfo, _not_ about the kernel implementation and self contained #defines (that I'd preferred if they really meant cpu_has and not can_I_use too, but that's an our internal thing not visible from userspace). fxsr and xmm in /proc/cpuinfo in 2.4.0, 2.4.1-pre[12], and 2.2.* means "cpu_has" and _not_ "can_I_use". So anybody using the fxsr and xmm in the "flags" row of /proc/cpuinfo as the "can_I_use" will break in any kernel before 2.4.1-pre3. Anybody reading fxsr and xmm as "cpu_has" will break in any kernel after 2.4.1-pre2. This all I meant when I said that 2.4.1-pre3 broke /proc/cpuinfo. I'd prefer if /proc/cpuinfo wasn't broken. That's all. Andrea - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/