From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 963237B3DA; Fri, 23 Feb 2024 12:25:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708691109; cv=none; b=N/9dLTmH4l+GwKH7i8yV9lnjufjLKVjpzYYOqRMWnCrrtNSPrdnBzq+OvWebKluM9VRXPrzQFvlJW1dnuTTxe+dKgDk0EFWURW4mZOp0b6m5n8Z6bXu8kO5IhXERbLQ56OE5JFcPrP2+iJhbWFWUkggZBZSTJEdywMcbX0pBuqw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708691109; c=relaxed/simple; bh=MaYmzslx1mf+A0NsaTa/pwiRoRWhmyCe7uHLHoWcvWk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ZkwjT30xUU0zTpmw6Gq9anGn+5XcOCxN/stqJldOtLY4ok6mn3yNTKU6ZcSN+ZTA2Xf+0GZxqhMnVJloTGjjyW+4T5v/Rwazt+rU5DRDAU+zFDebka7vt6rQQ1lOsBwacceDZja8jyzW8Apc3DGN8jp2FBUIkcM5p/8wr0JdSKA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QZzh6hfe; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QZzh6hfe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2AA8AC433C7; Fri, 23 Feb 2024 12:25:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708691109; bh=MaYmzslx1mf+A0NsaTa/pwiRoRWhmyCe7uHLHoWcvWk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QZzh6hfeQeMNWZYdbqEaxioTBGZ+mJt/NHcqk+dArheg7i59OcGjeBTfZPmvFQE4d JdsZtv6LFy/0QAGQEFyiGAquMPB2JTsp4NVilxCKsoLE78YzNu9RT3/sgaYv6ROwu9 hJO1OBBiuX1TVmdMwaCjr12HAHnq+9lOR392OElPmJPTx9TvoHhOGSOvY4BofL4+NL Lt72yrgSF6zPkSYE5jZO4WY3mVGHSSyPLV5b5zb44b3EukMiqd0EZgIKr8yFcKgSoL pVskg+jGQpmFMq+grGHvxhGKogtpNjgQrNVqHd8K/p9gY0Mrl/iKfQPobzpQDZWghu I0PCQlsfhY17Q== Date: Fri, 23 Feb 2024 13:25:06 +0100 From: Frederic Weisbecker To: "Paul E. McKenney" Cc: Boqun Feng , linux-kernel@vger.kernel.org, rcu@vger.kernel.org, Neeraj Upadhyay Subject: Re: [PATCH v2 0/6] RCU tasks fixes for v6.9 Message-ID: References: <20240217012745.3446231-1-boqun.feng@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Thu, Feb 22, 2024 at 02:09:17PM -0800, Paul E. McKenney wrote: > On Thu, Feb 22, 2024 at 05:52:23PM +0100, Frederic Weisbecker wrote: > > Le Fri, Feb 16, 2024 at 05:27:35PM -0800, Boqun Feng a écrit : > > > Hi, > > > > > > This series contains the fixes of RCU tasks for v6.9. You can also find > > > the series at: > > > > > > git://git.kernel.org/pub/scm/linux/kernel/git/boqun/linux.git rcu-tasks.2024.02.14a > > > > > > Changes since v1: > > > > > > * Update with Paul's rework on "Eliminate deadlocks involving > > > do_exit() and RCU task" > > > > > > The detailed list of changes: > > > > > > Paul E. McKenney (6): > > > rcu-tasks: Repair RCU Tasks Trace quiescence check > > > rcu-tasks: Add data to eliminate RCU-tasks/do_exit() deadlocks > > > rcu-tasks: Initialize data to eliminate RCU-tasks/do_exit() deadlocks > > > rcu-tasks: Maintain lists to eliminate RCU-tasks/do_exit() deadlocks > > > rcu-tasks: Eliminate deadlocks involving do_exit() and RCU tasks > > > > Food for later thoughts and further improvements: would it make sense to > > call exit_rcu_tasks_start() on fork() instead and rely solely on > > each CPUs' rtp_exit_list instead of the tasklist? > > It might well. > > One big advantage of doing that is the ability to incrementally traverse > the tasks. But is there some good way of doing that to the full task > lists? If so, everyone could benefit. What do you mean by incrementally? You mean being able to cond_resched() in the middle of the tasks iteration? Yeah not sure that's possible... Thanks. > > Thanx, Paul > > > Thanks. > > > > > rcu-tasks: Maintain real-time response in rcu_tasks_postscan() > > > > > > include/linux/rcupdate.h | 4 +- > > > include/linux/sched.h | 2 + > > > init/init_task.c | 1 + > > > kernel/fork.c | 1 + > > > kernel/rcu/tasks.h | 110 ++++++++++++++++++++++++++++++--------- > > > 5 files changed, 90 insertions(+), 28 deletions(-) > > > > > > -- > > > 2.43.0 > > > > > > > >