Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753608AbcC3GpD (ORCPT ); Wed, 30 Mar 2016 02:45:03 -0400 Received: from casper.infradead.org ([85.118.1.10]:39045 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753258AbcC3GpA (ORCPT ); Wed, 30 Mar 2016 02:45:00 -0400 Date: Wed, 30 Mar 2016 08:44:55 +0200 From: Peter Zijlstra To: Steven Rostedt Cc: Juri Lelli , Wanpeng Li , Ingo Molnar , Kirill V Tkhai , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v3] sched/deadline: do not try to push tasks if pinned task switches to dl Message-ID: <20160330064455.GQ3408@twins.programming.kicks-ass.net> References: <1413938203-224610-1-git-send-email-wanpeng.li@linux.intel.com> <544779D1.4060309@arm.com> <20160329184722.0d54b946@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160329184722.0d54b946@gandalf.local.home> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 603 Lines: 12 On Tue, Mar 29, 2016 at 06:47:22PM -0400, Steven Rostedt wrote: > I'm looking at some old changes for sched-deadline, and I stumbled > across this. As I'm working on sched deadline tests, I've discovered > that they can't have cpu affinity. They are limited to their sched > domains. That is, sched deadline tasks have whatever affinity that the > domain they happen to be in has. > > Is there a condition where rq != task_rq(p) and p->nr_cpus_allowed > 1 > isn't true? When holding rq->lock, no. I suppose the patch was just to mirror rt and someone 'forgot' about the extra constraints on dl tasks.