From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756585AbaCEEii (ORCPT ); Tue, 4 Mar 2014 23:38:38 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:45923 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754777AbaCEEih (ORCPT ); Tue, 4 Mar 2014 23:38:37 -0500 Date: Tue, 4 Mar 2014 20:38:58 -0800 From: Greg Kroah-Hartman To: Roland Dreier Cc: "linux-kernel@vger.kernel.org" , Andrew Morton , Arjan van de Ven , shli@kernel.org Subject: Re: [PATCH] Revert "driver core: synchronize device shutdown" Message-ID: <20140305043858.GA2494@kroah.com> References: <1393991871-1743-1-git-send-email-roland@kernel.org> <20140305040929.GA31130@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.22 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 04, 2014 at 08:15:36PM -0800, Roland Dreier wrote: > > Hm, no one seems to have said anything for the past 5 years about this. > > It definitely is hard to hit -- you have to do "shutdown" or "reboot" > right as something schedules async work. In our case we have some > systems with a large and slightly flaky SAS fabric, so there's a > constant level of re-probing SCSI disks, and we occasionally see > reboots hanging due to waiting for never-finishing sd probe async > work. > > AFAICT the synchronization does nothing useful and is just a remnant > of a patch series where the real meat didn't get applied. But of > course it would be great if Shaohua could confirm my understanding. Shaohua's email address seems to now bounce :( Arjan, any thoughts? greg k-h