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 9244BC6778C for ; Thu, 5 Jul 2018 17:07:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9D43E24053 for ; Thu, 5 Jul 2018 17:07:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amarulasolutions.com header.i=@amarulasolutions.com header.b="YgLGF+qR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9D43E24053 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 S1754221AbeGERG4 (ORCPT ); Thu, 5 Jul 2018 13:06:56 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:37088 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754071AbeGERGt (ORCPT ); Thu, 5 Jul 2018 13:06:49 -0400 Received: by mail-wm0-f65.google.com with SMTP id n17-v6so12056418wmh.2 for ; Thu, 05 Jul 2018 10:06:48 -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=wpeJFQAXVQlH+H/mGB26++XrajgOrz307ujkuW3sBf8=; b=YgLGF+qRzi4Vw0pxQ4m+0grxEwKRb0Ko/qDEfzg2pbaqVupFCmN133YxwwgAU1Lfhr MtxR/+jzhXu1i8JB4HE4abpnBXqZPg8hDbVL+TiLIoLbdnIIjr8l86DwlX5ty6G9vUKJ Jw+boTxYAkzRq5OlBt9RdpuwDtIHXL03h6uuk= 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=wpeJFQAXVQlH+H/mGB26++XrajgOrz307ujkuW3sBf8=; b=qy+zRvyC3xyFbFhDyvYBGwlM7V7CwIEqHMA8I3zoCNaMU8ZTgSwE2kE1867WdBmwuJ q5EZrUhzbdAB++LoTT9OoAHJTsi0Y7D01JbEBTeqYmsBK0nd7HEoQKFRdUaqsDOdWuzj wg8DcxrgAf/9pJHR/E2AnBlB8K+T0BVU58FmDzFxZKmz7Ok48Hz1nq0WYjT0DyfJwvnW nA1MFg/mc2oaHAZmiG63xKm3IIFnr7tNmeT6VAFe/xtVO02kxOp6nzmdIYK/CSGXzHcN kpiT9GcHarrY53ZNePG1Gi5yFcnN9lVTjDIMWjBJ1IPthFxNznvTmVofiXXmBoWFEwhL Lcug== X-Gm-Message-State: APt69E1iUAYofPH7MqoUiTub0Dy6FC8YbGV/eGVtcp8a48RVrOOakH3R 4rZIFN0CORrl7zNNUsRHueCYZA== X-Google-Smtp-Source: AAOMgpcLEBALWSR8EATKoVjyZzmpCR5r9/lNYICnqhq+B1qS3ZZbAFshUmomnXgYp+2FTVGoB7C5Uw== X-Received: by 2002:a1c:9e8a:: with SMTP id h132-v6mr4462862wme.48.1530810408011; Thu, 05 Jul 2018 10:06:48 -0700 (PDT) Received: from andrea ([94.230.152.15]) by smtp.gmail.com with ESMTPSA id k13-v6sm4143349wrr.14.2018.07.05.10.06.46 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 05 Jul 2018 10:06:47 -0700 (PDT) Date: Thu, 5 Jul 2018 19:06:36 +0200 From: Andrea Parri To: "Paul E. McKenney" Cc: Alan Stern , Will Deacon , LKMM Maintainers -- Akira Yokosawa , Boqun Feng , David Howells , Jade Alglave , Luc Maranget , Nicholas Piggin , Peter Zijlstra , Kernel development list , dlustig@nvidia.com Subject: Re: [PATCH 2/2] tools/memory-model: Add write ordering by release-acquire and by locks Message-ID: <20180705170636.GA2380@andrea> References: <20180704121103.GB26941@arm.com> <20180705153140.GO3593@linux.vnet.ibm.com> <20180705153906.GA2345@andrea> <20180705165848.GR3593@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180705165848.GR3593@linux.vnet.ibm.com> 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 Thu, Jul 05, 2018 at 09:58:48AM -0700, Paul E. McKenney wrote: > On Thu, Jul 05, 2018 at 05:39:06PM +0200, Andrea Parri wrote: > > > > At any rate, it looks like instead of strengthening the relation, I > > > > should write a patch that removes it entirely. I also will add new, > > > > stronger relations for use with locking, essentially making spin_lock > > > > and spin_unlock be RCsc. > > > > > > Only in the presence of smp_mb__after_unlock_lock() or > > > smp_mb__after_spinlock(), correct? Or am I confused about RCsc? > > > > There are at least two definitions of RCsc: one as documented in the header > > comment for smp_mb__after_spinlock() or rather in the patch under review..., > > one as processor architects used to intend it. ;-) > > Searching isn't working for me all that well this morning, so could you > please send me a pointer to that patch? Sorry, I meant in _this patch_: "RCsc" as ordering everything except for W -> R, without the barriers above (_informally, the current LKMM misses the W -> W order only). Andrea > > Thanx, Paul >