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 E5D2EC388F7 for ; Tue, 10 Nov 2020 20:33:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 83B9620781 for ; Tue, 10 Nov 2020 20:33:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="iD6NGpE1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726428AbgKJUde (ORCPT ); Tue, 10 Nov 2020 15:33:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726179AbgKJUde (ORCPT ); Tue, 10 Nov 2020 15:33:34 -0500 Received: from mail-qk1-x743.google.com (mail-qk1-x743.google.com [IPv6:2607:f8b0:4864:20::743]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE848C0613D3 for ; Tue, 10 Nov 2020 12:33:33 -0800 (PST) Received: by mail-qk1-x743.google.com with SMTP id n132so11745127qke.1 for ; Tue, 10 Nov 2020 12:33:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=FGyjU1VFt03gTjbteYJEMdl1u0ziLYUtvD1NXemfJhs=; b=iD6NGpE1mnBrvgAsnOHd2EJKsUjVra3puLElxMvH9dayS1Y4J7BdSu8POnN/3tqDx3 TgHnN0b9/e1BZjEEPF6k89aK9eODBtg9FhzicC8MxgUwuuYE6jpsRMLLdzG7uOltOsdL 1PhqdXX9Hkj8XMvsBrOwwoxUBOqdW8hTx7df4= 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; bh=FGyjU1VFt03gTjbteYJEMdl1u0ziLYUtvD1NXemfJhs=; b=O3bo3BIG7hHc1Z0ZZ97LtuL3ekMR2WjTZHyTmwiNQ13UwPKpfbQbgfv41xyNi3U9CT 7H/+NxRG5agyP3vOUnC0Nu5WalN0vIS8lMh9yFDXP+ksUnK6fL5K5o7dGGO6OA+AxibE iJBe6c4mOlwSrFewyidlN8YCDuwFXpJsAUnusoAuWh+JW/XL/DqBtmBQopHZD0UIu6p9 wiMbbbvLrNmpzgdWESPFpmQwfwxYs70WpfSPrn1V0tIX5GD2hYnbKMiUoE8jHOBF0Z/Z gZTpgNbh0SmUTgULx1UmjYfxVX/yTd6bILqlNCbd6mKMxTqLdrZdp9JUbDDNQRedSXb4 VUXw== X-Gm-Message-State: AOAM533uXfaPHVK+qPkjdy4az3avVyPsIGjtdqevoy3i6BlyHih8x6ON Ln9OVkWGGa1xOvWKOV7gbcehkQ== X-Google-Smtp-Source: ABdhPJxa69TxULwtqWM4g1jhzML48igFEJTuMp1hchP6B5ueOhZOEsls5SPVIjL0X2Uw3UmSQ1ZAfw== X-Received: by 2002:a37:86c4:: with SMTP id i187mr21508004qkd.371.1605040409776; Tue, 10 Nov 2020 12:33:29 -0800 (PST) Received: from localhost ([2620:15c:6:411:cad3:ffff:feb3:bd59]) by smtp.gmail.com with ESMTPSA id b4sm5591796qti.64.2020.11.10.12.33.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 10 Nov 2020 12:33:29 -0800 (PST) Date: Tue, 10 Nov 2020 15:33:28 -0500 From: Joel Fernandes To: Peter Zijlstra Cc: "Paul E. McKenney" , 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 Subject: Re: [PATCH tip/core/rcu 2/4] docs: Update RCU's hotplug requirements with a bit about design Message-ID: <20201110203328.GA694269@google.com> References: <20201105230444.GA18574@paulmck-ThinkPad-P72> <20201105230510.18660-2-paulmck@kernel.org> <20201109122317.GM2594@hirez.programming.kicks-ass.net> <20201109162452.GK3249@paulmck-ThinkPad-P72> <20201109171433.GL2611@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201109171433.GL2611@hirez.programming.kicks-ass.net> Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org On Mon, Nov 09, 2020 at 06:14:33PM +0100, Peter Zijlstra wrote: > On Mon, Nov 09, 2020 at 08:24:52AM -0800, Paul E. McKenney wrote: > > On Mon, Nov 09, 2020 at 01:23:17PM +0100, Peter Zijlstra wrote: > > > 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 "``". > > > > It was there to start with, but good point. How about the commit > > below? > > Much appreciated, thanks! Thanks for making the change, I built it and it looks good in my web browser ;-). BTW, these APIs are obsolete due to consolidation. Paul could you remove them from the document?: synchronize_rcu_bh(), synchronize_rcu_bh_expedited(), call_rcu_bh(), rcu_barrier_bh(). thanks! -Joel