From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753313Ab3LMSwo (ORCPT ); Fri, 13 Dec 2013 13:52:44 -0500 Received: from mail-qc0-f175.google.com ([209.85.216.175]:64420 "EHLO mail-qc0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752967Ab3LMSwn (ORCPT ); Fri, 13 Dec 2013 13:52:43 -0500 Date: Fri, 13 Dec 2013 13:52:37 -0500 From: Tejun Heo To: "Rafael J. Wysocki" , Jens Axboe Cc: tomaz.solc@tablix.org, aaron.lu@intel.com, linux-kernel@vger.kernel.org, Oleg Nesterov , Greg Kroah-Hartman , Fengguang Wu Subject: Re: Writeback threads and freezable Message-ID: <20131213185237.GD27070@htj.dyndns.org> References: <20131213174932.GA27070@htj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131213174932.GA27070@htj.dyndns.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 13, 2013 at 12:49:32PM -0500, Tejun Heo wrote: > I'm not completely sure what to do. We can make an exception for > bdi_wq and thaw it early but that breaks the guarantee that bdi is > frozen between device suspend and resume invocations and we might as > well just remove WQ_FREEZABLE from it. I don't know. Ugh, so I removed WQ_FREEZABLE on bdi and the same deadlock now happens through jbd2 which is a freezable kthread. This whole kthread freezer thing is rotten and fundamentally broken. :( -- tejun