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=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 89453C2D0A3 for ; Fri, 6 Nov 2020 16:57:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 22D9422202 for ; Fri, 6 Nov 2020 16:57:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726176AbgKFQ5U (ORCPT ); Fri, 6 Nov 2020 11:57:20 -0500 Received: from netrider.rowland.org ([192.131.102.5]:51731 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1726075AbgKFQ5U (ORCPT ); Fri, 6 Nov 2020 11:57:20 -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-arch@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