From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicholas Mc Guire Subject: Re: [patch 0/6] 3.14-rt1 fixes Date: Sat, 3 May 2014 10:32:57 +0200 Message-ID: <20140503083257.GA16242@opentech.at> References: <1399029159.5233.124.camel@marge.simpson.net> <5363840B.6020402@pavlinux.ru> <1399031023.5233.145.camel@marge.simpson.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: pavel@pavlinux.ru, RT , Sebastian Andrzej Siewior , Steven Rostedt , Thomas Gleixner To: Mike Galbraith Return-path: Received: from hofr.at ([212.69.189.236]:35380 "EHLO mail.hofr.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750920AbaECIll (ORCPT ); Sat, 3 May 2014 04:41:41 -0400 Content-Disposition: inline In-Reply-To: <1399031023.5233.145.camel@marge.simpson.net> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Fri, 02 May 2014, Mike Galbraith wrote: > On Fri, 2014-05-02 at 15:39 +0400, Pavel Vasilyev wrote: > > 02.05.2014 15:12, Mike Galbraith ??????????: > > > The following patches are fixes that fell out of testing rt1. Patches > > > 1-4 are intended to be folded into existing patches, 5-6 are > > > replacements. > > > > > > fold: > > > 1/6 - preempt-lazy-support.patch > > > 2/6 - x86-preempt-lazy.patch > > > 3/6 - hotplug-light-get-online-cpus.patch > > > 4/6 - stomp-machine-raw-lock.patch > > > > > > replace: > > > 5/6 - (prep) > > > 6/6 - stomp-machine-deal-clever-with-stopper-lock.patch > > > > > > drop: (buggy - calls migrate_disable() _after_ maybe blocking) > > > migrate_disable-pushd-down-in-atomic_dec_and_spin_lo.patch > > > > Why would calling migrate_disable be buggy after blocking ? at that point any per cpu data is not yet being accessed so its perfectly fine to lock->block -> migrate -> unblock->lock -> migrate_disable on a new CPU -> access per_cpu object -> migrate_enable -> unlock what problems would there be ? thx! hofrat