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=-12.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,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 36E78C433ED for ; Mon, 3 May 2021 04:34:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0DF8461152 for ; Mon, 3 May 2021 04:34:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232223AbhECEfX (ORCPT ); Mon, 3 May 2021 00:35:23 -0400 Received: from server.lespinasse.org ([63.205.204.226]:58935 "EHLO server.lespinasse.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229462AbhECEfX (ORCPT ); Mon, 3 May 2021 00:35:23 -0400 DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=lespinasse.org; i=@lespinasse.org; q=dns/txt; s=srv-14-ed; t=1620016470; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to : from; bh=IVSN4rXFsAqhRrOBaOG8oTadR0XsOpnayasis5eGn9U=; b=GiTjC8TtRi8A2CDiu0777x7lS1aQSG/UClzMN3PifJJ0qYNcWlGgoD08V63aSXdrhQaCD a0zQ+St3HpALbCICA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lespinasse.org; i=@lespinasse.org; q=dns/txt; s=srv-14-rsa; t=1620016470; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to : from; bh=IVSN4rXFsAqhRrOBaOG8oTadR0XsOpnayasis5eGn9U=; b=HtWQf/wqqDk6NgXnD50nv0QWm5dqjfsaZFbvL2Nw4gMOyDbtnDhWr0HW+xpDBBYtTC52O xek042nGdx7+Fx9JDYaqolvI6ByvUSHoVsgheAUf4SwqiKTzoHWoj128m50WOruyxmtDI/h tIcrAvsMACJcOWPm2Ir3rH3SMrYv5OI9CcQyHBow4g3v4oGH0DzSMmz3fEo955xd/dGneZ7 g71w5qh/S4h+5GF8jRzyDRkjf/IcAHtrZVUalbkbGyppCNXhiRiIws6mzPCZgDUKF4OM0aA ztyf3YdFTvD4Cgy33gs7gSITuLuFgjF39rbxqkgctAwWXd0GcQp6HJzahL6w== Received: by server.lespinasse.org (Postfix, from userid 1000) id 13274160055; Sun, 2 May 2021 21:34:30 -0700 (PDT) Date: Sun, 2 May 2021 21:34:30 -0700 From: Michel Lespinasse To: "Paul E. McKenney" Cc: Michel Lespinasse , Andy Lutomirski , Linux-MM , Laurent Dufour , Peter Zijlstra , Michal Hocko , Matthew Wilcox , Rik van Riel , Andrew Morton , Suren Baghdasaryan , Joel Fernandes , Rom Lemarchand , Linux-Kernel Subject: Re: [RFC PATCH 13/37] mm: implement speculative handling in __handle_mm_fault(). Message-ID: <20210503043430.GA16059@lespinasse.org> References: <20210407014502.24091-14-michel@lespinasse.org> <20210428145823.GA856@lespinasse.org> <20210428161108.GP975577@paulmck-ThinkPad-P17-Gen-1> <20210429000225.GC10973@lespinasse.org> <20210429155250.GV975577@paulmck-ThinkPad-P17-Gen-1> <20210429183412.GA278623@paulmck-ThinkPad-P17-Gen-1> <20210429211758.GE10973@lespinasse.org> <20210503034049.GQ975577@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210503034049.GQ975577@paulmck-ThinkPad-P17-Gen-1> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, May 02, 2021 at 08:40:49PM -0700, Paul E. McKenney wrote: > @@ -634,6 +644,12 @@ do { \ > * sections, invocation of the corresponding RCU callback is deferred > * until after the all the other CPUs exit their critical sections. > * > + * In recent kernels, synchronize_rcu() and call_rcu() also wait for > + * regions of code with preemption disabled, including regions of code > + * with interrupts or softirqs disabled. If your kernel is old enough > + * for synchronize_sched() to be defined, only code enclosed within > + * rcu_read_lock() and rcu_read_unlock() are guaranteed to be waited for. > + * > * Note, however, that RCU callbacks are permitted to run concurrently > * with new RCU read-side critical sections. One way that this can happen > * is via the following sequence of events: (1) CPU 0 enters an RCU You still have "old enough" / "recent kernels" here. But maybe it's OK given that you added relevant version numbers elsewhere. Everything else looks great to me. Thanks, -- Michel "walken" Lespinasse