From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752664AbbBWMvd (ORCPT ); Mon, 23 Feb 2015 07:51:33 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50765 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752330AbbBWMvc (ORCPT ); Mon, 23 Feb 2015 07:51:32 -0500 Message-ID: <54EB2238.7010005@redhat.com> Date: Mon, 23 Feb 2015 07:51:04 -0500 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: Andy Lutomirski CC: Borislav Petkov , "Maciej W. Rozycki" , Ingo Molnar , Oleg Nesterov , X86 ML , "linux-kernel@vger.kernel.org" , Linus Torvalds Subject: Re: [RFC PATCH] x86, fpu: Use eagerfpu by default on all CPUs References: <20150221093150.GA27841@gmail.com> <20150221163840.GA32073@pd.tnic> <20150221172914.GB32073@pd.tnic> <20150222110629.GB7529@pd.tnic> <54EA8641.6040609@redhat.com> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 02/23/2015 12:22 AM, Andy Lutomirski wrote: > On Sun, Feb 22, 2015 at 5:45 PM, Rik van Riel > wrote: >> One implication of this is that in kernel mode, we can no longer >> just assume that the user space FPU state is always loaded, and >> we need to check for that (like the lazy FPU code does today). I >> would really like to keep that code around, for obvious reasons >> :) > > I like that stuff, except for the fact that it still has code that > depends on whether we're in eager or lazy mode, even though eager > is a little less eager with your patches. Ideally I'd like to see > your patches applied *and* lazy mode removed. The latest version of my code (which I should forward-port again to the latest tip bits) simplifies things a lot. It moves all new task handling to switch_fpu_finished(), which is called from do_notify_resume(). At that point we either load the FPU context, or we set CR0.TS. - -- All rights reversed -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJU6yI3AAoJEM553pKExN6DyQEH/13E0T6wsII5L+0W1D0WU4v5 F2SmU74zvCv+RhRl/0npvKRQC3IkZ/peM9h/1PU/r61Y39VhexUxiUZ86afzz4KJ ogPNEs6HZ8UYSji6RPlVsuJJ4vCsZ9GA+27JwKGzLUG1NfniL0qlc93rl+f3ZfFm 5H4bjtcO361Am15yKkFPRl/0PKqRhMDa4tzJGkvvCaJ+k195Ik0a7WXjOlGdIeJA 5Q1D0qaAccXtwfNjqhxIfTBi1LV2a1/jCKF8ktxGJ2+Ywvau9blJnPfD8vUf9JL2 9/le1kyNU3h8B2lU0jIi4a2Y/CcU47heEUy5htmoo6wChQWAy/pR8JaE6++qWqI= =ee/J -----END PGP SIGNATURE-----