From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756160AbaCEEJK (ORCPT ); Tue, 4 Mar 2014 23:09:10 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:45749 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755007AbaCEEJI (ORCPT ); Tue, 4 Mar 2014 23:09:08 -0500 Date: Tue, 4 Mar 2014 20:09:29 -0800 From: Greg Kroah-Hartman To: Roland Dreier Cc: linux-kernel@vger.kernel.org, Andrew Morton , Shaohua Li , Arjan van de Ven Subject: Re: [PATCH] Revert "driver core: synchronize device shutdown" Message-ID: <20140305040929.GA31130@kroah.com> References: <1393991871-1743-1-git-send-email-roland@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1393991871-1743-1-git-send-email-roland@kernel.org> 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 07:57:51PM -0800, Roland Dreier wrote: > From: Roland Dreier > > This reverts commit 401097ea4b89846d66ac78f7f108d49c2e922d9c. The > original changelog said: > > A patch series to make .shutdown execute asynchronously. Some drivers's > shutdown can take a lot of time. The patches can help save some shutdown > time. The patches use Arjan's async API. > > This patch: > > synchronize all tasks submitted by .shutdown > > However, I'm not able to find any evidence that any other patches from > this series were applied, nor am I able to find any async tasks that are > scheduled in a .shutdown context. > > On the other hand, we see occasional hangs on shutdown that appear to be > caused by the async_synchronize_full() in device_shutdown() waiting > forever for the async probing in sd if a SCSI disk shows up at just the > wrong time — the system starts the probe, but begins shutting down and > tears down too much of the SCSI driver to finish the probe. > > If we had any async shutdown tasks, I guess the right fix would be to > create a "shutdown" async domain and have device_shutdown() only wait > for that domain. But since there apparently are no async shutdown > tasks, we can just revert the waiting. > > Signed-off-by: Roland Dreier Hm, no one seems to have said anything for the past 5 years about this. Shaohua and Arjan, any objection to this being applied? thanks, greg k-h