From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCHSET v6] blk-mq scheduling framework To: Hannes Reinecke , 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> <33510a1f-e681-2c5b-137e-3986b1f91779@suse.de> Cc: osandov@osandov.com, bart.vanassche@sandisk.com From: Jens Axboe Message-ID: <67fdc091-443d-2180-2af9-5bda96356d18@kernel.dk> Date: Mon, 16 Jan 2017 08:47:18 -0700 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 List-ID: On 01/16/2017 08:16 AM, Jens Axboe wrote: > On 01/16/2017 08:12 AM, Jens Axboe wrote: >> On 01/16/2017 01:11 AM, Hannes Reinecke wrote: >>> 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 >> >> Odd, not sure that's me. What did you pull my branch into? And what is the >> sha of the stuff you pulled in? > > Forgot to ask, please send me the fio job you ran here. Nevermind, it's a mainline bug that's fixed in -rc4: commit a12f1ae61c489076a9aeb90bddca7722bf330df3 Author: Shaohua Li Date: Tue Dec 13 12:09:56 2016 -0800 aio: fix lock dep warning -- Jens Axboe