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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 800E8C433E0 for ; Thu, 4 Jun 2020 13:14:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4FE3120772 for ; Thu, 4 Jun 2020 13:14:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591276453; bh=wQgVns7AYqWR4w7SQT/eBFlehH8s1tQ6Y1+38K2sstQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Pg7LsNcOHYseLK+aoJ2TfcgQ7BbQhHWulq3qdIbTYnOpA7FXo/X3kVHpaU3grmCca I/J4KqXXd7dqfXHjsMnnjTSqMwLHZ3tNxHoxcNKKbfjA/Xj/Y7Mty37mBTTACaFMKm oFy9LCk/A+jmy2Ra/EkyheoGeA3vvzgFZSTUXN9o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728428AbgFDNOM (ORCPT ); Thu, 4 Jun 2020 09:14:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:59950 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726003AbgFDNOL (ORCPT ); Thu, 4 Jun 2020 09:14:11 -0400 Received: from localhost (lfbn-ncy-1-324-171.w83-196.abo.wanadoo.fr [83.196.159.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4BB2E206C3; Thu, 4 Jun 2020 13:14:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591276451; bh=wQgVns7AYqWR4w7SQT/eBFlehH8s1tQ6Y1+38K2sstQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=gF3vCuB1NL9722USg+0cpVofl1MvmbqORPkJ1wEBNE06D+iefH4BwIXz7/sX8MF/n aXB9/h62EaMkRG/aZ2PuIxBzYtTtAkHGMPa6qkXB3Q/OVabQWmnMMUbVJlxXTnwHni fYA9tWXeSWHBlS9gFaOYfE3etMALS3jd9ySS40Ps= Date: Thu, 4 Jun 2020 15:14:09 +0200 From: Frederic Weisbecker To: Joel Fernandes Cc: "Paul E . McKenney" , LKML , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Josh Triplett Subject: Re: [PATCH 08/10] rcu: Allow to deactivate nocb on a CPU Message-ID: <20200604131409.GB27571@lenoir> References: <20200513164714.22557-1-frederic@kernel.org> <20200513164714.22557-9-frederic@kernel.org> <20200526212017.GE76276@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200526212017.GE76276@google.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 26, 2020 at 05:20:17PM -0400, Joel Fernandes wrote: > On Wed, May 13, 2020 at 06:47:12PM +0200, Frederic Weisbecker wrote: > > Allow a CPU's rdp to quit the callback offlined mode. > > nit: s/offlined/offloaded/ ? Oh, looks like I did that everywhere :) > > > The switch happens on the target with IRQs disabled and rdp->nocb_lock > > held to avoid races between local callbacks handling and kthread > > offloaded callbacks handling. > > nocb_cb kthread is first parked to avoid any future race with > > concurrent rcu_do_batch() executions. Then the cblist is set to offloaded > > so that the nocb_gp kthread ignores this rdp. > > nit: you mean cblist is set to non-offloaded mode right? Ah right! > > +static void __rcu_nocb_rdp_deoffload(struct rcu_data *rdp) > > +{ > > + unsigned long flags; > > + struct rcu_node *rnp = rdp->mynode; > > + > > + printk("De-offloading %d\n", rdp->cpu); > > nit: s/printk/pr_debug/ ? Ok. Thanks!