Received: by 10.223.176.46 with SMTP id f43csp279291wra; Thu, 18 Jan 2018 17:20:32 -0800 (PST) X-Google-Smtp-Source: ACJfBovpwVtmfy6Pn+9QtgrOlgur1+YLUjSyWhpXDonswzBuutPNijIHGIn7pvqov8EqPo1/U8TY X-Received: by 10.98.58.5 with SMTP id h5mr40108168pfa.169.1516324832569; Thu, 18 Jan 2018 17:20:32 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1516324832; cv=none; d=google.com; s=arc-20160816; b=u6VxGcLmRA5vskO0Z+XcagRB5pncB5cR+xFxKyW38sOo11DOsr1DMxvAHn9dU1FxB1 D9TyRmwr0HlVy2lXw3kDoachWPNoYlZgvOzBZYS9nB44kuqmrIbXEhe7HjAElotz6/M2 RgMRZIS/qPlRrK96b/7D8hsyuEfLziUqlC+0r1ReQfu5SW9ClaVROcB+8RfRgXD0CcNr hNd8zkMUBJ8FXbzDKPhTjjGeAsyPPDH0EdKgST97BjXmjveBxPPSFhEH2tcowo0PtP9t l9DnPQmdkIO+LyuXTUZHgTYws5iJwQqwCG7b3Zbe8w/wlHYCNRIamQLGF66tPQftB40r 2bjg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:arc-authentication-results; bh=7GGQf6PRFpJR6gCrNK9PVzEYojsgwdu9x2MRNNTrXZk=; b=BB3tNR6CxTcPTJ1Rq4C0wOnhd0bV913LFJYObChw70w7mclEggvPSdWtx/CKoNIleS 8Uyt6LOrr73zkbjX84jtWCtkX3DNJ6uHRBnB5QDv2kaOXZuZIx1V3TSgB/Cbcf7AX4MB QumOETuUbbdFW0Bnbt66b3R/gL8XrJzwVifVPf+TcIV2zOYj8Z7vLs0WCW+W6MC7giUt KqgQubNE2GYCfuNcySVTJDvsirFK6qqKfGQabqgJG0FtDWIIbVJMChGqAphZx6xtmH8c jWGK+GK0Q5hL2blbL0pd5sg4ebRUCNPkgvbJ/KXcA//OGrdgProPXxK3ZNE1WUneBPuJ tx7w== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id l30-v6si377978plg.123.2018.01.18.17.20.18; Thu, 18 Jan 2018 17:20:32 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755404AbeASBSm (ORCPT + 99 others); Thu, 18 Jan 2018 20:18:42 -0500 Received: from violet.fr.zoreil.com ([92.243.8.30]:51723 "EHLO violet.fr.zoreil.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754872AbeASBSe (ORCPT ); Thu, 18 Jan 2018 20:18:34 -0500 X-Greylist: delayed 404 seconds by postgrey-1.27 at vger.kernel.org; Thu, 18 Jan 2018 20:18:33 EST Received: from violet.fr.zoreil.com (localhost [127.0.0.1]) by violet.fr.zoreil.com (8.14.9/8.14.9) with ESMTP id w0J1BJCi015930; Fri, 19 Jan 2018 02:11:19 +0100 Received: (from romieu@localhost) by violet.fr.zoreil.com (8.14.9/8.14.5/Submit) id w0J1BI7b015929; Fri, 19 Jan 2018 02:11:18 +0100 Date: Fri, 19 Jan 2018 02:11:18 +0100 From: Francois Romieu To: Peter Zijlstra Cc: Jia-Ju Bai , nic_swsd@realtek.com, alexander.h.duyck@redhat.com, David Miller , dhowells@redhat.com, paulmck@linux.vnet.ibm.com, will.deacon@arm.com, netdev@vger.kernel.org, Linux Kernel Mailing List Subject: Re: net: r8169: a question of memory barrier in the r8169 driver Message-ID: <20180119011118.GB15920@electric-eye.fr.zoreil.com> References: <9a373156-41e5-a78b-cd31-c4b9bdba2696@gmail.com> <20180118150658.GE2249@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180118150658.GE2249@hirez.programming.kicks-ass.net> X-Organisation: Land of Sunshine Inc. User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Peter Zijlstra : [...] > There is only 1 variable afaict. Memory barriers need at least 2 in > order to be able to do _anything_. I don't get your point: why don't {cur_tx, dirty_tx} qualify as said two variables ? -- Ueimor