From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751081AbdAPIL7 (ORCPT ); Mon, 16 Jan 2017 03:11:59 -0500 Received: from mx2.suse.de ([195.135.220.15]:45891 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750892AbdAPILd (ORCPT ); Mon, 16 Jan 2017 03:11:33 -0500 Subject: Re: [PATCHSET v6] blk-mq scheduling framework To: Jens Axboe , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org References: <1484170803-9311-1-git-send-email-axboe@fb.com> <5850a4ad-74a1-8d30-e865-fbd35679e84f@suse.de> <2e968ed9-7269-488b-4c38-b318ad99ed3f@fb.com> <3cda10cb-b74e-0f6c-bbda-37d366b92ad0@suse.de> <62478d65-8bfb-49bf-c26e-d64daf37c001@suse.de> <80fc3190-3607-b909-66fb-c69ced180335@kernel.dk> Cc: osandov@osandov.com, bart.vanassche@sandisk.com From: Hannes Reinecke Message-ID: <33510a1f-e681-2c5b-137e-3986b1f91779@suse.de> Date: Mon, 16 Jan 2017 09:11:30 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 MIME-Version: 1.0 In-Reply-To: <80fc3190-3607-b909-66fb-c69ced180335@kernel.dk> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/13/2017 05:02 PM, Jens Axboe wrote: > On 01/13/2017 09:00 AM, Jens Axboe wrote: >> On 01/13/2017 08:59 AM, Hannes Reinecke wrote: >>> On 01/13/2017 04:34 PM, Jens Axboe wrote: >>>> On 01/13/2017 08:33 AM, Hannes Reinecke wrote: >>> [ .. ] >>>>> Ah, indeed. >>>>> There is an ominous udev rule here, trying to switch to 'deadline'. >>>>> >>>>> # cat 60-ssd-scheduler.rules >>>>> # do not edit this file, it will be overwritten on update >>>>> >>>>> ACTION!="add", GOTO="ssd_scheduler_end" >>>>> SUBSYSTEM!="block", GOTO="ssd_scheduler_end" >>>>> >>>>> IMPORT{cmdline}="elevator" >>>>> ENV{elevator}=="*?", GOTO="ssd_scheduler_end" >>>>> >>>>> KERNEL=="sd*[!0-9]", ATTR{queue/rotational}=="0", >>>>> ATTR{queue/scheduler}="deadline" >>>>> >>>>> LABEL="ssd_scheduler_end" >>>>> >>>>> Still shouldn't crash the kernel, though ... >>>> >>>> Of course not, and it's not a given that it does, it could just be >>>> triggering after the device load and failing like expected. But just in >>>> case, can you try and disable that rule and see if it still crashes with >>>> MQ_DEADLINE set as the default? >>>> >>> Yes, it does. >>> Same stacktrace as before. >> >> Alright, that's as expected. I've tried with your rule and making >> everything modular, but it still boots fine for me. Very odd. Can you >> send me your .config? And are all the SCSI disks hanging off ahci? Or >> sdb specifically, is that ahci or something else? > > Also, would be great if you could pull: > > git://git.kernel.dk/linux-block blk-mq-sched > > into current 'master' and see if it still reproduces. I expect that it > will, but just want to ensure that it's a problem in the current code > base as well. > Actually, it doesn't. Seems to have resolved itself with the latest drop. However, not I've got a lockdep splat: Jan 16 09:05:02 lammermuir kernel: ------------[ cut here ]------------ Jan 16 09:05:02 lammermuir kernel: WARNING: CPU: 29 PID: 5860 at kernel/locking/lockdep.c:3514 lock_release+0x2a7/0x490 Jan 16 09:05:02 lammermuir kernel: DEBUG_LOCKS_WARN_ON(depth <= 0) Jan 16 09:05:02 lammermuir kernel: Modules linked in: raid0 mpt3sas raid_class rpcsec_gss_krb5 auth_rpcgss nfsv4 nfs lockd grace fscache e Jan 16 09:05:02 lammermuir kernel: fb_sys_fops ahci uhci_hcd ttm ehci_pci libahci ehci_hcd serio_raw crc32c_intel drm libata usbcore hpsa Jan 16 09:05:02 lammermuir kernel: CPU: 29 PID: 5860 Comm: fio Not tainted 4.10.0-rc3+ #540 Jan 16 09:05:02 lammermuir kernel: Hardware name: HP ProLiant ML350p Gen8, BIOS P72 09/08/2013 Jan 16 09:05:02 lammermuir kernel: Call Trace: Jan 16 09:05:02 lammermuir kernel: dump_stack+0x85/0xc9 Jan 16 09:05:02 lammermuir kernel: __warn+0xd1/0xf0 Jan 16 09:05:02 lammermuir kernel: ? aio_write+0x118/0x170 Jan 16 09:05:02 lammermuir kernel: warn_slowpath_fmt+0x4f/0x60 Jan 16 09:05:02 lammermuir kernel: lock_release+0x2a7/0x490 Jan 16 09:05:02 lammermuir kernel: ? blkdev_write_iter+0x89/0xd0 Jan 16 09:05:02 lammermuir kernel: aio_write+0x138/0x170 Jan 16 09:05:02 lammermuir kernel: do_io_submit+0x4d2/0x8f0 Jan 16 09:05:02 lammermuir kernel: ? do_io_submit+0x413/0x8f0 Jan 16 09:05:02 lammermuir kernel: SyS_io_submit+0x10/0x20 Jan 16 09:05:02 lammermuir kernel: entry_SYSCALL_64_fastpath+0x23/0xc6 Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg)