Received: by 2002:a05:6a10:16a7:0:0:0:0 with SMTP id gp39csp1412139pxb; Fri, 6 Nov 2020 09:01:19 -0800 (PST) X-Google-Smtp-Source: ABdhPJzQyLbNwua3s+6ZGFMG4IJ8c/hzN9d3szkBq7lZmcGy+JaXybc1brP2oeJq2btfUb21p6RL X-Received: by 2002:ac2:446b:: with SMTP id y11mr1326017lfl.403.1604682079255; Fri, 06 Nov 2020 09:01:19 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1604682079; cv=none; d=google.com; s=arc-20160816; b=xtYXTd54ez8PAHciOIkNZgC8S4JUKbRsvtIxieQ9Df14+cL3HUO4AoJqveHxW7AfoN t68o6riDw9mOjwuSG3IifyGiAAVXnqjCHvMU8M+xFd91IOgQ208aiv5Ofg2yamP+qT/f ElxutnIdq7g3UDpw2xSLOW/VocROpcIaTEXfe8NLXK0QQ9zy+E5LWfZ94ub/25LkOAwQ fxCOODIj/7G9w1ikhsdWYyXvAMPe8raPQN6Lt//IzFNJ44eM05vMA7LBarLaDj+7LwoF Z3UYEiekBTdPPdG63GmDi6GoImnv4CSf/A2avhrEm7yK0nvAK14tsyGWBc9gN3aPIQG8 2sgw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:user-agent:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date; bh=kCSvBrzo72F0Y0p8vjdAUkwqUfe18wYRVjfiWOPVd9M=; b=WZ1F3Tjq4mxPCWy3kV+nvLf4E7n/Vb6SxJCoVpZWvjUt6ab+nqCYLUuxmHW+Dvuabz /KpiBeaspBC1y//DmpsLjALRiixzEpryvVm/+Dn4npeNYOAMbAdMN4QlClsJFwdTYUhf GT4q90YQGaWrOpqJC43MM3j0XFF9bwGKBSJpXJDdqkQL/uvZtL/3rttYe63zPvOQurte ikg2aQtsPYra1ibRevnscUqXR5BHLwZNrVCLo3AEPIsEZrg4VCc8Je2Z5+e3uTyqbXko iXjoubddRoAHbG0ZUfgGoSk0RUzwImviFlsVLgivTUmyzB7W1JnNtqpsTRNR6fIzU5li Ez+Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id z2si1359948ejc.253.2020.11.06.09.00.55; Fri, 06 Nov 2020 09:01:19 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726765AbgKFQ5V (ORCPT + 99 others); Fri, 6 Nov 2020 11:57:21 -0500 Received: from netrider.rowland.org ([192.131.102.5]:58017 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1726139AbgKFQ5V (ORCPT ); Fri, 6 Nov 2020 11:57:21 -0500 Received: (qmail 47225 invoked by uid 1000); 6 Nov 2020 11:56:54 -0500 Date: Fri, 6 Nov 2020 11:56:54 -0500 From: Alan Stern To: paulmck@kernel.org Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, kernel-team@fb.com, mingo@kernel.org, parri.andrea@gmail.com, will@kernel.org, peterz@infradead.org, boqun.feng@gmail.com, npiggin@gmail.com, dhowells@redhat.com, j.alglave@ucl.ac.uk, luc.maranget@inria.fr, akiyks@gmail.com Subject: Re: [PATCH memory-model 3/8] tools/memory-model: Document categories of ordering primitives Message-ID: <20201106165654.GB47039@rowland.harvard.edu> References: <20201105215953.GA15309@paulmck-ThinkPad-P72> <20201105220017.15410-3-paulmck@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201105220017.15410-3-paulmck@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 05, 2020 at 02:00:12PM -0800, paulmck@kernel.org wrote: > From: "Paul E. McKenney" > > The Linux kernel has a number of categories of ordering primitives, which > are recorded in the LKMM implementation and hinted at by cheatsheet.txt. > But there is no overview of these categories, and such an overview > is needed in order to understand multithreaded LKMM litmus tests. > This commit therefore adds an ordering.txt as well as extracting a > control-dependencies.txt from memory-barriers.txt. It also updates the > README file. > > [ paulmck: Apply Akira Yokosawa file-placement feedback. ] > [ paulmck: Apply Alan Stern feedback. ] > [ paulmck: Apply self-review feedback. ] > Signed-off-by: Paul E. McKenney > --- > diff --git a/tools/memory-model/Documentation/README b/tools/memory-model/Documentation/README > index 2d9539f..a50ea81 100644 > --- a/tools/memory-model/Documentation/README > +++ b/tools/memory-model/Documentation/README > @@ -41,13 +50,21 @@ README > cheatsheet.txt > Quick-reference guide to the Linux-kernel memory model. > > +control-dependencies.txt > + Guide to preventing compiler optimizations from destroying > + your control dependencies. > + > explanation.txt > - Detailed description of the memory model. > + Detailed description of the memory model in detail. A redundantly redundant change. Alan