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Subject: Re: [PATCHSET v6] blk-mq scheduling framework
To: Jens Axboe <axboe@fb.com>, linux-kernel@vger.kernel.org,
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Cc: osandov@osandov.com, bart.vanassche@sandisk.com
From: Hannes Reinecke <hare@suse.de>
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Date: Fri, 13 Jan 2017 16:59:03 +0100
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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.

Cheers

Hannes
-- 
Dr. Hannes Reinecke		   Teamlead Storage & Networking
hare@suse.de			               +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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