From mboxrd@z Thu Jan 1 00:00:00 1970 From: Karl Tomlinson Subject: Re: hang during suspend to RAM when bcache cache device is attached Date: Fri, 19 May 2017 14:12:28 +1200 Message-ID: <878tltr3w3.fsf@karlt.net> References: <87pof8rmqb.fsf@karlt.net> <87ziebqhjf.fsf@karlt.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from [195.159.176.226] ([195.159.176.226]:54235 "EHLO blaine.gmane.org" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S932211AbdESCPP (ORCPT ); Thu, 18 May 2017 22:15:15 -0400 Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1dBXRa-0001sM-32 for linux-bcache@vger.kernel.org; Fri, 19 May 2017 04:15:06 +0200 In-Reply-To: (Eric Wheeler's message of "Thu, 18 May 2017 17:03:33 +0000 (UTC)") Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: linux-bcache@vger.kernel.org Eric Wheeler writes: > Try the patch below, this is the only deadlock fix that isn't upstream > that I'm aware of. Your trace above doesn't indicate any bcache > functions, so this could be hard to troubleshoot. Thanks for the suggestion, but I think I've found the real cause. I wasn't able to reproduce with 4.11.1, which I suspect is due to https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/drivers/nvme/host/core.c?h=v4.11.1&id=302ad8cc09339ea261eef58a8d5f4a116a8ffda5 which fixes an issue that matches the symptoms I've seen. The history of that change is http://lists.infradead.org/pipermail/linux-nvme/2017-March/008593.html https://patchwork.kernel.org/patch/9589187/ http://lists.infradead.org/pipermail/linux-nvme/2017-January/007617.html FWIW I was not able to reproduce with a filesystem directly on an nvme partition, but I guess stacked devices or bcache changed things enough to trigger.