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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=ham 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 048F9C43144 for ; Mon, 25 Jun 2018 08:29:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AFEC5255E7 for ; Mon, 25 Jun 2018 08:29:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amarulasolutions.com header.i=@amarulasolutions.com header.b="KmGu4WE3" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AFEC5255E7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=amarulasolutions.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754342AbeFYI3d (ORCPT ); Mon, 25 Jun 2018 04:29:33 -0400 Received: from mail-wr0-f171.google.com ([209.85.128.171]:35583 "EHLO mail-wr0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754080AbeFYI3b (ORCPT ); Mon, 25 Jun 2018 04:29:31 -0400 Received: by mail-wr0-f171.google.com with SMTP id c13-v6so2750282wrq.2 for ; Mon, 25 Jun 2018 01:29:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amarulasolutions.com; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=mnr+Nr+2rMhZCwmr3I2/Y2jpho0XSbY1HRMR/OFVW1k=; b=KmGu4WE3+OSSCrW7ptX9spj7hN1oMPj0CdLOndxUp+Na4pvRbXIewVlRBxOeU4pK2m Q+7PyV5ESlruENPKQDwDKO6to2j/J4chL+zKzWTw+Rkox68BkiaZKd3dNiiC8gzcGPxw dX2/EENPFfKyfH7SM+jEFZ2f6V/2Y6duT4ITc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=mnr+Nr+2rMhZCwmr3I2/Y2jpho0XSbY1HRMR/OFVW1k=; b=OZ7/p2xtXDUlufc+u2bPDhpEclmz0x1dEpnsf1bC7J560pUux+RjJi1/dScvk3vJ10 VzLwUeCYaQ73uVV3TDRR7+aIXfZ6xIXb8mZtTYKYiI5/i/kF9kZ/k16i+EwKaN3u46Rz Wa04oQxgdWF+3r3RvdAbHp1A/LXLTdKWlryWR6+AY8xC3YKfaGXVW1uqKAJxLTqqkvHL px5/ZymVr2nnuiJECkMAQpa1ZekELa5oS5EjKVoxvkJ1rRU0mTBOEVv/wfsE3WtWvzMb gaBEPPUNyWQk1D9vXEPDxEIcBnOI3NoaUy9DQ07jCRociwhknNtHky/kTY44yNKlBaZw AHyg== X-Gm-Message-State: APt69E2S/rwELoO9rSJwSh04ZeYU0DGfBRf5aXFPCcdphpQgCYbogESx pOW1hQWb/3fh9IrP+ttEZAjjYA== X-Google-Smtp-Source: AAOMgpc2ImJjKYkjE4tkNml77fco6W05cU5nfOU5zc0AK53HsYHHG/lQpUQ5x44u+q/2jGKv7vzEdQ== X-Received: by 2002:adf:e447:: with SMTP id t7-v6mr9607079wrm.145.1529915370472; Mon, 25 Jun 2018 01:29:30 -0700 (PDT) Received: from andrea (85.100.broadband17.iol.cz. [109.80.100.85]) by smtp.gmail.com with ESMTPSA id z128-v6sm10167931wmz.18.2018.06.25.01.29.29 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 25 Jun 2018 01:29:29 -0700 (PDT) Date: Mon, 25 Jun 2018 10:29:23 +0200 From: Andrea Parri To: Peter Zijlstra Cc: Alan Stern , Will Deacon , LKMM Maintainers -- Akira Yokosawa , Boqun Feng , David Howells , Jade Alglave , Luc Maranget , Nicholas Piggin , "Paul E. McKenney" , Kernel development list Subject: Re: [PATCH 2/2] tools/memory-model: Add write ordering by release-acquire and by locks Message-ID: <20180625082923.GA5808@andrea> References: <20180622080928.GB7601@arm.com> <20180625073229.GR2494@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180625073229.GR2494@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 25, 2018 at 09:32:29AM +0200, Peter Zijlstra wrote: > > I have yet to digest the rest of the discussion, however: > > On Fri, Jun 22, 2018 at 02:09:04PM -0400, Alan Stern wrote: > > The LKMM uses the same CAT code for acquire/release and lock/unlock. > > (In essence, it considers a lock to be an acquire and an unlock to be a > > release; everything else follows from that.) Treating one differently > > from the other in these tests would require some significant changes. > > It wouldn't be easy. > > That is problematic, acquire+release are very much simpler operations > than lock+unlock. > > At the very least, lock includes a control-dependency, where acquire > does not. I don't see how this is relevant here; roughly, "if something is guaranteed by a control-dependency, that is also guaranteed by an acquire". Right? ;) Andrea