From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94C6EC432C0 for ; Fri, 29 Nov 2019 17:08:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 715A1215F1 for ; Fri, 29 Nov 2019 17:08:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727040AbfK2RIU (ORCPT ); Fri, 29 Nov 2019 12:08:20 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:49200 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726971AbfK2RIU (ORCPT ); Fri, 29 Nov 2019 12:08:20 -0500 Received: from bigeasy by Galois.linutronix.de with local (Exim 4.80) (envelope-from ) id 1iajkV-0002WT-0w; Fri, 29 Nov 2019 18:08:07 +0100 Date: Fri, 29 Nov 2019 18:08:06 +0100 From: 'Sebastian Andrzej Siewior' To: David Laight Cc: Barret Rhoden , Borislav Petkov , Josh Bleecher Snyder , Rik van Riel , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , Thomas Gleixner , Ingo Molnar , "ian@airs.com" , Austin Clements , David Chase Subject: Re: [PATCH v2] x86/fpu: Don't cache access to fpu_fpregs_owner_ctx Message-ID: <20191129170806.f6gvbpsom74njxpb@linutronix.de> References: <20191126202026.csrmjre6vn2nxq7c@linutronix.de> <20191127124243.u74osvlkhcmsskng@linutronix.de> <20191127140754.GB3812@zn.tnic> <20191128085306.hxfa2o3knqtu4wfn@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019-11-29 16:57:42 [+0000], David Laight wrote: > Should both fpregs_lock() and fpregs_unlock() contain a barrier() (or "memory" clobber) > do stop the compiler moving anything across them? They already do. > David Sebastian