Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932300AbWJCQsK (ORCPT ); Tue, 3 Oct 2006 12:48:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932297AbWJCQsJ (ORCPT ); Tue, 3 Oct 2006 12:48:09 -0400 Received: from xenotime.net ([66.160.160.81]:13488 "HELO xenotime.net") by vger.kernel.org with SMTP id S932300AbWJCQsH (ORCPT ); Tue, 3 Oct 2006 12:48:07 -0400 Date: Tue, 3 Oct 2006 09:49:26 -0700 From: Randy Dunlap To: Linus Torvalds Cc: akpm , Jesper Juhl , Andi Kleen , Linux Kernel Mailing List Subject: Re: [PATCH/RFC] Math-emu kills the kernel on Athlon64 X2 Message-Id: <20061003094926.0e99d13f.rdunlap@xenotime.net> In-Reply-To: References: <9a8748490609181518j2d12e4f0l2c55e755e40d38c2@mail.gmail.com> <9a8748490609191414m6748f2fu521637df29ef9e8e@mail.gmail.com> <20061002191638.093fde85.rdunlap@xenotime.net> <20061002213809.7a3f995f.rdunlap@xenotime.net> <20061003092339.999d0011.rdunlap@xenotime.net> Organization: YPO4 X-Mailer: Sylpheed version 2.2.9 (GTK+ 2.8.10; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1608 Lines: 39 On Tue, 3 Oct 2006 09:37:45 -0700 (PDT) Linus Torvalds wrote: > > > On Tue, 3 Oct 2006, Randy Dunlap wrote: > > > > Yes, that works. > > Ok. I'll commit that simple thing, and add a comment on why we're > apparently doing the same thing twice (you do need _both_ of those things: > the "disable_x86_fxsr" will make sure all other CPU's also get cleared, > while the "clear_bit()" will clear it immediately on the boot CPU) > > I'll leave the no387/nofxsr linking alone for now. The main reason to use > no387 would seem to be just testing that emulation works at all, and I > guess we can just tell people to use the "no387 nofxsr" combination. > > So Randy, with this you can boot all the way into user space, and some FP > apps still work too? My few trivial float and double apps work. Is there any particular test/workload that you want me to run? > (Of course, user-space may be buggy and use SSE etc without testing for > whether the CPU actually supports it - if the install process has > installed some special SSE-version of a library depending on what the CPU > claimed at that point, or if somebody uses "cpuid" directly rather than > asking the kernel. So there's no way we're going to _guarantee_ that this > works in user space, but at least a well-behaved user-space that works on > a i486 should hopefully be ok). --- ~Randy - 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/