Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754780AbaBAURU (ORCPT ); Sat, 1 Feb 2014 15:17:20 -0500 Received: from terminus.zytor.com ([198.137.202.10]:33579 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933375AbaBAURH (ORCPT ); Sat, 1 Feb 2014 15:17:07 -0500 Message-ID: <52ED562B.60703@zytor.com> Date: Sat, 01 Feb 2014 12:16:43 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Linus Torvalds CC: Suresh Siddha , Nate Eldredge , Thomas Gleixner , Ingo Molnar , the arch/x86 maintainers , stable , Linux Kernel Mailing List , Maarten Baert , Jan Kara , George Spelvin , Pekka Riikonen Subject: Re: [PATCH] Make math_state_restore() save and restore the interrupt flag References: <52ED4C96.6020703@zytor.com> In-Reply-To: X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/01/2014 11:46 AM, Linus Torvalds wrote: > > .. which *does* actually bring up something that might work, and might > be a good idea: remove the "restore math state or set TS" from the > normal kernel paths *entirely*, and move it to the "return to user > space" phase. > The task switch code would have to be aware in case of preemption, though. The nice thing about *that* is that we could probably completely drop the notion that we can't preempt an FPU-using kernel task. -hpa -- 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/