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=-7.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, 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 678BDC433E0 for ; Wed, 13 May 2020 18:15:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0709D2065C for ; Wed, 13 May 2020 18:15:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589393740; bh=DRVgA+6vHSXA9HT1ILwpPT8oWoxmN3Nwo5ztWxLd0w8=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=JeevsNiLIDXltBsWo/wY5FzOmqsbEI0u681Mf9EFS8zYO9BHvVnLf8s9Xjxe5ZJc7 DnE2drAYt+Xtdf4nr/uegT68cN1MZ4mgFU+hkD3UbG49KOfRnB/UasOnaSRWpRvKuW Usq5obj4n1p9cXYqnn94ES4OGMRfm/cplSA6mTQc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390101AbgEMSPi (ORCPT ); Wed, 13 May 2020 14:15:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:59430 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733175AbgEMSPi (ORCPT ); Wed, 13 May 2020 14:15:38 -0400 Received: from paulmck-ThinkPad-P72.home (unknown [50.39.105.78]) (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 3842020659; Wed, 13 May 2020 18:15:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589393738; bh=DRVgA+6vHSXA9HT1ILwpPT8oWoxmN3Nwo5ztWxLd0w8=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=B4HiprMPYKY2LGIXSa2C3vRE/sysCHRAaJSHwpyKXRu0YO6jGfjBkXNbgYGNOZzNV JrhxliQAfAZhA9Qv3L99pwbUh2HPLZIcPO6OWlwRDn7WeMlzFLXdHdtldjKMl0HAPA 6Bgh3UG+ARH+NElpOIf30gMishdIvXmEnd+RprD8= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 5B59E352352C; Wed, 13 May 2020 11:15:37 -0700 (PDT) Date: Wed, 13 May 2020 11:15:37 -0700 From: "Paul E. McKenney" To: Frederic Weisbecker Cc: LKML , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Joel Fernandes , Josh Triplett Subject: Re: [PATCH 00/10] rcu: Allow a CPU to leave and reenter NOCB state Message-ID: <20200513181537.GS2869@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <20200513164714.22557-1-frederic@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200513164714.22557-1-frederic@kernel.org> 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 Wed, May 13, 2020 at 06:47:04PM +0200, Frederic Weisbecker wrote: > This is a necessary step toward making nohz_full controllable through > cpuset. Next step should be to allow a CPU to be nocb even if it wasn't > part of the nocb set on boot. > > The core design of this set is mostly based on suggestions from Paul > of course. > > git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git > rcu/nohz > > HEAD: 31cb4ee9da4e9cc6314498ff22d83f0d872b1a88 Very cool!!! A few comments on individual commits on a quick first scan, and more later. Thanx, Paul > Thanks, > Frederic > --- > > Frederic Weisbecker (10): > rcu: Directly lock rdp->nocb_lock on nocb code entrypoints > rcu: Use direct rdp->nocb_lock operations on local calls > rcu: Make locking explicit in do_nocb_deferred_wakeup_common() > rcu: Implement rcu_segcblist_is_offloaded() config dependent > rcu: Remove useless conditional nocb unlock > rcu: Make nocb_cb kthread parkable > rcu: Temporarily assume that nohz full CPUs might not be NOCB > rcu: Allow to deactivate nocb on a CPU > rcu: Allow to re-offload a CPU that used to be nocb > rcu: Nocb (de)activate through sysfs > > > include/linux/rcu_segcblist.h | 2 + > include/linux/rcupdate.h | 4 ++ > kernel/cpu.c | 23 +++++++ > kernel/rcu/rcu_segcblist.c | 6 +- > kernel/rcu/rcu_segcblist.h | 8 ++- > kernel/rcu/tree.c | 24 +++---- > kernel/rcu/tree.h | 2 +- > kernel/rcu/tree_plugin.h | 149 ++++++++++++++++++++++++++++++++++-------- > 8 files changed, 172 insertions(+), 46 deletions(-)