Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D98C7C433EF for ; Thu, 25 Nov 2021 00:57:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345142AbhKYBAk (ORCPT ); Wed, 24 Nov 2021 20:00:40 -0500 Received: from mail.kernel.org ([198.145.29.99]:53484 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236767AbhKYA6j (ORCPT ); Wed, 24 Nov 2021 19:58:39 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id C726D610C8; Thu, 25 Nov 2021 00:55:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1637801729; bh=xdymPQyK7gdFsIQR3HCpcKrt/ANx7OykyFUrbxE2A6U=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MjZ+iAsrXCa3dxljlCRNd/fiDcwzg38jpgN2OgC3HgSrAguMGEmoxcc5V0HgSrX4B jPQSOsf7MrGu70W510vc361ReqZ/ZcVFbuqJK/bfRfvWOxaJuePBPaTJn69qwAlSGl IuiIYf+Z3HjnVI7WrqE3F/nFmCFRpm9PUuzIJE/hMovCPG+FxYDiyj3W3BOV0eXfC/ MGJC4MUZAYK9Q4KC1Ln2EjdLCen/V0Bv8f8UjNL8QdoJ8QqmRBGzsBnddGkeNeOXFD l7KcmpuTMKcbLgF0ZDC5WBDNlrphwUu8zoKlq+u0gJXejXIHNWSPFsIYP6V8w6Y3zD RxHSQgbaQ1+Kg== Date: Thu, 25 Nov 2021 01:55:26 +0100 From: Frederic Weisbecker To: "Paul E. McKenney" Cc: LKML , Uladzislau Rezki , Neeraj Upadhyay , Boqun Feng , Josh Triplett , Joel Fernandes , rcu@vger.kernel.org, yury.norov@gmail.com Subject: Re: [PATCH 5/6] rcu/nocb: Allow empty "rcu_nocbs" kernel parameter Message-ID: <20211125005526.GA490855@lothringen> References: <20211123003708.468409-1-frederic@kernel.org> <20211123003708.468409-6-frederic@kernel.org> <20211125004720.GV641268@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211125004720.GV641268@paulmck-ThinkPad-P17-Gen-1> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 24, 2021 at 04:47:20PM -0800, Paul E. McKenney wrote: > On Tue, Nov 23, 2021 at 01:37:07AM +0100, Frederic Weisbecker wrote: > > If a user wants to boot without any CPU in offloaded mode initially but > > with the possibility to offload them later using cpusets, provide a way > > to simply pass an empty "rcu_nocbs" kernel parameter which will enforce > > the creation of dormant nocb kthreads. > > Huh. This would have been a use for Yury Norov's "none" bitmask > specifier. ;-) This must be the last missing piece before we can finally support NR_CPUS=0 ;) > > I pulled this one in with the usual wordsmithing. Thanks!