From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751657AbdF1M4l (ORCPT ); Wed, 28 Jun 2017 08:56:41 -0400 Received: from isilmar-4.linta.de ([136.243.71.142]:54918 "EHLO isilmar-4.linta.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751492AbdF1M4k (ORCPT ); Wed, 28 Jun 2017 08:56:40 -0400 Date: Wed, 28 Jun 2017 12:03:57 +0200 From: Dominik Brodowski To: Tejun Heo Cc: Marcel Holtmann , "Gustavo F. Padovan" , Johan Hedberg , LKML , linux-bluetooth@vger.kernel.org Subject: Re: 4.12.0-rc6+: WQ_MEM_RECLAIM hci0:hci_power_off is flushing !WQ_MEM_RECLAIM events:btusb_work Message-ID: <20170628100357.GA5675@light.dominikbrodowski.net> References: <20170625182149.GA18000@light.dominikbrodowski.net> <20170627152032.GA2289@htj.duckdns.org> <83EA7A09-DDFB-4CEB-8F45-52BFDCE3C6DF@holtmann.org> <20170627173946.GE2289@htj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170627173946.GE2289@htj.duckdns.org> User-Agent: Mutt/1.8.3 (2017-05-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hej Tejun and Marcel, On Tue, Jun 27, 2017 at 01:39:46PM -0400, Tejun Heo wrote: > Hello, Marcel. > > On Tue, Jun 27, 2017 at 07:28:40PM +0200, Marcel Holtmann wrote: > > >> On my Dell XPS 13 9343 (x86_64), the following warning was logged right > > >> after a resume from suspend-to-mem (not on *every* resume, though, so it > > >> might be hard to reproduce). The kernel is v4.12.0-rc6+ as of 94a6df251dd0, > > >> and I don't really use bluetooth, though the drivers are loaded: > > >> > > >> PM: Finishing wakeup. > > >> OOM killer enabled. > > >> Restarting tasks ... done. > > >> Bluetooth: hci0: read Intel version: 370710018002030d00 > > >> Bluetooth: hci0: Intel Bluetooth firmware file: intel/ibt-hw-37.7.10-fw-1.80.2.3.d.bseq > > >> Bluetooth: hci0: Intel Bluetooth firmware patch completed and activated > > >> ... > > >> workqueue: WQ_MEM_RECLAIM hci0:hci_power_off is flushing !WQ_MEM_RECLAIM events:btusb_work > > > > > > So, WQ_MEM_RECLAIM has to be transitive; otherwise, it doesn't mean > > > anything. I have a hard time believing that bluetooth actually needs > > > WQ_MEM_RECLAIM unless people mount nfs through a bluetooth tethered > > > phone. Would it be possible to remove WQ_MEM_RECLAIM from these > > > workqueues? > > > > frankly I do not remember. We used what was recommended to use. I > > know that the only requirement in one case is that it is a truly > > single workqueue. > > Heh, I don't remember either. I wonder whether there is an existing > dependency chain from network side which triggers the warning. > Dominik, can you please see whether the following patch makes the > warning go away while not triggering new ones? Alas, the warning was not reproducible beforehand -- with the patch applied, no warning was emitted during a few suspend-and-resume cycles. Whether bluetooth still works as expected, I cannot tell, as I do not use it. Thanks, Dominik