Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934242AbcJTLVu (ORCPT ); Thu, 20 Oct 2016 07:21:50 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:47939 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932353AbcJTLVs (ORCPT ); Thu, 20 Oct 2016 07:21:48 -0400 Date: Thu, 20 Oct 2016 13:21:45 +0200 From: Sebastian Andrzej Siewior To: Mike Galbraith Cc: Thomas Gleixner , LKML , linux-rt-users , Steven Rostedt Subject: Re: [rfc patch] hotplug: Call mmdrop_delayed() in sched_cpu_dying() if PREEMPT_RT_FULL Message-ID: <20161020112145.tyz6pcoimysha3jz@linutronix.de> References: <20161006085228.jl6rpszdp5c2p2nr@linutronix.de> <1476956043.18007.15.camel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1476956043.18007.15.camel@gmail.com> User-Agent: NeoMutt/20161014 (1.7.1) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 711 Lines: 17 On 2016-10-20 11:34:03 [+0200], Mike Galbraith wrote: > My 64 core box just passed an hour running Steven's hotplug stress > script along with stockfish and futextests (tip-rt.today w. hotplug > hacks you saw a while back), and seems content to just keep on grinding > away. Without it, box quickly becomes a doorstop. This is new. It is v4.7-rc1 new. The hotplug rework moved the notified around and after e9cd8fa4fcfd ("sched/migration: Move calc_load_migrate() into CPU_DYING") f2785ddb5367 ("sched/hotplug: Move migration CPU_DYING to sched_cpu_dying()") we have no more CPU_DEAD, just CPU_DYING which is invoked with interrupts off. I don't see anything wrong with pushing this over to RCU. Sebastian