Re: [PATCHSET v6] blk-mq scheduling framework

[Jens Axboe]

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?

-- 
Jens Axboe