Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752008AbeAPWxu (ORCPT + 1 other); Tue, 16 Jan 2018 17:53:50 -0500 Received: from mail.kernel.org ([198.145.29.99]:34068 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751882AbeAPWxt (ORCPT ); Tue, 16 Jan 2018 17:53:49 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0B9CA2175A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=frederic@kernel.org Date: Tue, 16 Jan 2018 23:53:45 +0100 From: Frederic Weisbecker To: Mike Galbraith Cc: Luiz Capitulino , Ingo Molnar , LKML , Peter Zijlstra , Chris Metcalf , Thomas Gleixner , Christoph Lameter , "Paul E . McKenney" , Wanpeng Li , Rik van Riel Subject: Re: [GIT PULL] isolation: 1Hz residual tick offloading v3 Message-ID: <20180116225333.GB32665@lerouge> References: <1515039937-367-1-git-send-email-frederic@kernel.org> <20180112141813.32dcc84d@redhat.com> <20180116154055.GA27042@lerouge> <1516125498.6599.23.camel@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1516125498.6599.23.camel@gmx.de> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Tue, Jan 16, 2018 at 06:58:18PM +0100, Mike Galbraith wrote: > On Tue, 2018-01-16 at 16:41 +0100, Frederic Weisbecker wrote: > > On Fri, Jan 12, 2018 at 02:18:13PM -0500, Luiz Capitulino wrote: > > > > > Why are extending isolcpus= given that it's a deprecated interface? > > > Some people have already moved away from isolcpus= now, but with this > > > new feature they will be forced back to using it. > > > > I tried to remove isolcpus or at least change the way it works so that its > > effects are reversible (ie: affine the init task instead of isolating domains) > > but that got nacked due to the behaviour's expectations for userspace. > > So we paint ourselves into a static corner forever more, despite every > bit of this being all about "properties of sets of cpus", ie precisely > what cpusets was born to do. ?That's sad, dynamic wasn't that far away. Hence why we need to propagate "isolcpus=" to cpusets.