Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758792AbYF2McG (ORCPT ); Sun, 29 Jun 2008 08:32:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753465AbYF2Mb4 (ORCPT ); Sun, 29 Jun 2008 08:31:56 -0400 Received: from il.qumranet.com ([212.179.150.194]:19302 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753341AbYF2Mbz (ORCPT ); Sun, 29 Jun 2008 08:31:55 -0400 Message-ID: <486780BA.6010202@qumranet.com> Date: Sun, 29 Jun 2008 15:31:54 +0300 From: Avi Kivity User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Andi Kleen CC: Agner Fog , Arjan van de Ven , "H. Peter Anvin" , linux-kernel@vger.kernel.org Subject: Re: ABI change for device drivers using future AVX instruction set References: <48626514.2040905@agner.org> <20080625092224.736c2541@infradead.org> <4862ECAB.1040402@zytor.com> <4864CFA5.9050901@agner.org> <20080627072231.7337ba18@infradead.org> <4865F0DA.2050906@agner.org> <87myl5pyqo.fsf@basil.nowhere.org> <4866541F.1060709@agner.org> <20080628200231.GA21259@one.firstfloor.org> <48677313.8000804@qumranet.com> <48677E39.6000001@firstfloor.org> In-Reply-To: <48677E39.6000001@firstfloor.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1024 Lines: 39 Andi Kleen wrote: > Avi Kivity wrote: > > >> This is fixable. >> > > Sure nearly everything is fixable, but why would you want to do that? > > For me the best fix currently seems to be to just not do that > when it hurts. > > We already use sse in the kernel (raid), presumably disabling preemption there hurts some workloads. With sse/avx gaining more features, we may see more requirements for kernel fpu. >> We could change kernel_fpu_begin() not to disable >> preemption, but instead set a task flag. When we get the "no device" >> fault, if the flag is set, save the fpu state into the kernel fpu save >> area >> > > What kernel fpu save area do you mean? > A new one, of course. -- error compiling committee.c: too many arguments to function -- 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/