From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757918AbcBCRG4 (ORCPT ); Wed, 3 Feb 2016 12:06:56 -0500 Received: from mail-yk0-f169.google.com ([209.85.160.169]:35016 "EHLO mail-yk0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756674AbcBCRGy (ORCPT ); Wed, 3 Feb 2016 12:06:54 -0500 Date: Wed, 3 Feb 2016 12:06:52 -0500 From: Tejun Heo To: Mike Galbraith Cc: Michal Hocko , Jiri Slaby , Thomas Gleixner , Petr Mladek , Jan Kara , Ben Hutchings , Sasha Levin , Shaohua Li , LKML , stable@vger.kernel.org, Daniel Bilik Subject: Re: Crashes with 874bbfe600a6 in 3.18.25 Message-ID: <20160203170652.GI14091@mtj.duckdns.org> References: <20160122160903.GH32380@htj.duckdns.org> <1453515623.3734.156.camel@decadent.org.uk> <20160126093400.GV24938@quack.suse.cz> <20160126111438.GA731@pathway.suse.cz> <56B1C9E4.4020400@suse.cz> <20160203122855.GB6762@dhcp22.suse.cz> <20160203162441.GE14091@mtj.duckdns.org> <1454518913.6148.15.camel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1454518913.6148.15.camel@gmail.com> 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 On Wed, Feb 03, 2016 at 06:01:53PM +0100, Mike Galbraith wrote: > Hm, so it's ok to queue work to an offline CPU? What happens if it > doesn't come back for an eternity or two? Right now, it just loses affinity. A more interesting case is a cpu going offline whlie work items bound to the cpu are still running and the root problem is that we've never distinguished between affinity for correctness and optimization and thus can't flush or warn on the stagglers. The plan is to ensure that all correctness users specify the CPU explicitly. Once we're there, we can warn on illegal usages. Thanks. -- tejun