Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758347AbcJRBXb (ORCPT ); Mon, 17 Oct 2016 21:23:31 -0400 Received: from mail-vk0-f45.google.com ([209.85.213.45]:34947 "EHLO mail-vk0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755380AbcJRBXY (ORCPT ); Mon, 17 Oct 2016 21:23:24 -0400 MIME-Version: 1.0 In-Reply-To: <20161017234556.GA18947@test-lenovo> References: <1476734984-13839-1-git-send-email-riel@redhat.com> <1476734984-13839-2-git-send-email-riel@redhat.com> <20161017230416.GA18900@test-lenovo> <20161017234556.GA18947@test-lenovo> From: Andy Lutomirski Date: Mon, 17 Oct 2016 18:23:03 -0700 Message-ID: Subject: Re: [PATCH RFC 1/3] fpu/x86: add make_fpregs_active(_newstate) helper functions To: Yu-cheng Yu Cc: Rik van Riel , Dave Hansen , "linux-kernel@vger.kernel.org" , Ingo Molnar , Borislav Petkov , Linus Torvalds , Andrew Lutomirski , dave.hansen@intel.linux.com, Thomas Gleixner , "H. Peter Anvin" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 534 Lines: 13 On Mon, Oct 17, 2016 at 4:45 PM, Yu-cheng Yu wrote: > On Mon, Oct 17, 2016 at 04:30:47PM -0700, Andy Lutomirski wrote: >> Rik wants to add a different form of FPU laziness, and it would be >> simpler if we could just always copy from a kernel buffer. Does code >> to do that exist in the tree? > > If we know fpregs are not active at the time of the copy and compacted format > is the concern, can we use copyout_from_xsaves() in xstate.c? > Right, that. Rik, that could be an alternative solution. --Andy