Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934203AbcJQXrG (ORCPT ); Mon, 17 Oct 2016 19:47:06 -0400 Received: from mga05.intel.com ([192.55.52.43]:4758 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932580AbcJQXrC (ORCPT ); Mon, 17 Oct 2016 19:47:02 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,359,1473145200"; d="scan'208";a="1046079607" Date: Mon, 17 Oct 2016 16:45:56 -0700 From: Yu-cheng Yu To: Andy Lutomirski 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" Subject: Re: [PATCH RFC 1/3] fpu/x86: add make_fpregs_active(_newstate) helper functions Message-ID: <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 389 Lines: 9 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? Yu-cheng