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=-9.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 249F2C2D0A3 for ; Mon, 9 Nov 2020 12:23:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CB981206CB for ; Mon, 9 Nov 2020 12:23:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="QcGdbeqE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729038AbgKIMXk (ORCPT ); Mon, 9 Nov 2020 07:23:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729243AbgKIMXj (ORCPT ); Mon, 9 Nov 2020 07:23:39 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADCF2C0613D3; Mon, 9 Nov 2020 04:23:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=hElt3BjZoDAKcnNC0PKLQXKgb0IojHcRSCI9KVMCbJE=; b=QcGdbeqEhJuP4IMcgPzq4ULOLA BcgcuzO2xpaizHtmebW/NoCpFu/f/ZroWP//nQihcnQqEeQu09TThmJM1e3RQNhdkwEcQy30GI9mc ozGMfcKVC6FaZMsvEN9fl4fUrLiGmfmCBUskgxiYYWHKPdN9t/ZHr2DpGPWe1uQG1zOKfRbq/C1F0 KGTF5HgEyFBKX20RrmtnvLtUOEtCu5g8mO6/LbaGCrWQY87L0GojFUPoCdE8PYJjX0p65qc57X18B SNV+f8Ic47P+iNDNKlfTve6WAVb2cUsy8ST+pOlgSaT4IaO1yeg1TG3Dc73qcV3UyrczlUYJ6hFEG gpklj7MQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kc6Cd-0001Gf-9V; Mon, 09 Nov 2020 12:23:19 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id CC957306102; Mon, 9 Nov 2020 13:23:17 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id B8ACC203C5334; Mon, 9 Nov 2020 13:23:17 +0100 (CET) Date: Mon, 9 Nov 2020 13:23:17 +0100 From: Peter Zijlstra To: paulmck@kernel.org Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, mingo@kernel.org, jiangshanlai@gmail.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org Subject: Re: [PATCH tip/core/rcu 2/4] docs: Update RCU's hotplug requirements with a bit about design Message-ID: <20201109122317.GM2594@hirez.programming.kicks-ass.net> References: <20201105230444.GA18574@paulmck-ThinkPad-P72> <20201105230510.18660-2-paulmck@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201105230510.18660-2-paulmck@kernel.org> Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org On Thu, Nov 05, 2020 at 03:05:08PM -0800, paulmck@kernel.org wrote: > From: "Joel Fernandes (Google)" > > The rcu_barrier() section of the "Hotplug CPU" section discusses > deadlocks, however the description of deadlocks other than those involving > rcu_barrier() is rather incomplete. > > This commit therefore continues the section by describing how RCU's > design handles CPU hotplug in a deadlock-free way. > > Signed-off-by: Joel Fernandes (Google) > Signed-off-by: Paul E. McKenney > --- > .../RCU/Design/Requirements/Requirements.rst | 49 +++++++++++++++++----- > 1 file changed, 39 insertions(+), 10 deletions(-) > > diff --git a/Documentation/RCU/Design/Requirements/Requirements.rst b/Documentation/RCU/Design/Requirements/Requirements.rst > index 1ae79a1..98557fe 100644 > --- a/Documentation/RCU/Design/Requirements/Requirements.rst > +++ b/Documentation/RCU/Design/Requirements/Requirements.rst > @@ -1929,16 +1929,45 @@ The Linux-kernel CPU-hotplug implementation has notifiers that are used > to allow the various kernel subsystems (including RCU) to respond > appropriately to a given CPU-hotplug operation. Most RCU operations may > be invoked from CPU-hotplug notifiers, including even synchronous > -grace-period operations such as ``synchronize_rcu()`` and > -``synchronize_rcu_expedited()``. I was under the impression that this rst crap now recognises func() and you no longer need to make the text unreadable with "``".