From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751766AbcBYWBQ (ORCPT ); Thu, 25 Feb 2016 17:01:16 -0500 Received: from mail-yk0-f176.google.com ([209.85.160.176]:34089 "EHLO mail-yk0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751349AbcBYWBO (ORCPT ); Thu, 25 Feb 2016 17:01:14 -0500 Date: Thu, 25 Feb 2016 17:01:12 -0500 From: Tejun Heo To: Peter Chen Cc: Alan Stern , florian@mickler.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, usb-storage@lists.one-eyed-alien.net Subject: Re: Freezable workqueue blocks non-freezable workqueue during the system resume process Message-ID: <20160225220112.GM6092@mtj.duckdns.org> References: <20160223032056.GB12256@shlinux2.ap.freescale.net> <20160224072430.GC15452@shlinux2.ap.freescale.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160224072430.GC15452@shlinux2.ap.freescale.net> 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 Hello, Peter. On Wed, Feb 24, 2016 at 03:24:30PM +0800, Peter Chen wrote: > > You might want to complain to the block-layer people about this. I > > don't know if anything can be done to fix it. > > > > Or maybe flush_work and flush_delayed_work can be changed to avoid > > blocking if the workqueue is frozen. Tejun? > > > > I have a patch to show the root cause of this issue. > > http://www.spinics.net/lists/linux-usb/msg136815.html I don't get it. Why would it deadlock? Shouldn't things get rolling once the workqueues are thawed? Thanks. -- tejun