Hi Jens,
I'm not finding this fix in either current rc or for-5.2. Am I missing
something?
Thanks,
Paolo
> Il giorno 19 gen 2019, alle ore 15:36, Jens Axboe <axboe@xxxxxxxxx> ha scritto:
>
> On 1/19/19 4:13 AM, Kai Krakow wrote:
>> Am Fr., 18. Jan. 2019 um 18:34 Uhr schrieb Jens Axboe <axboe@xxxxxxxxx>:
>>>
>>> A previous commit moved the shallow depth and BFQ depth map calculations
>>> to be done at init time, moving it outside of the hotter IO path. This
>>> potentially causes hangs if the users changes the depth of the scheduler
>>> map, by writing to the 'nr_requests' sysfs file for that device.
>>>
>>> Add a blk-mq-sched hook that allows blk-mq to inform the scheduler if
>>> the depth changes, so that the scheduler can update its internal state.
>>>
>>> Reported-by: Paolo Valente <paolo.valente@xxxxxxxxxx>
>>> Fixes: f0635b8a416e ("bfq: calculate shallow depths at init time")
>>> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
>>
>> Works fine here in 4.18 as far as I could test (running a full backup,
>> some compilations and Gentoo package upgrades, filling memory with web
>> browsers to force swapping).
>>
>> $ grep ^ /sys/block/*/queue/nr_requests
>> /sys/block/bcache0/queue/nr_requests:128
>> /sys/block/bcache1/queue/nr_requests:128
>> /sys/block/bcache2/queue/nr_requests:128
>> /sys/block/bcache3/queue/nr_requests:128
>> /sys/block/bcache4/queue/nr_requests:128
>> /sys/block/sda/queue/nr_requests:256
>> /sys/block/sdb/queue/nr_requests:256
>> /sys/block/sdc/queue/nr_requests:256
>> /sys/block/sdd/queue/nr_requests:256
>> /sys/block/sde/queue/nr_requests:256
>> /sys/block/sdf/queue/nr_requests:256
>>
>> Tested-by: Kai Krakow <kai@xxxxxxxxxxx>
>
> Great, thanks for testing!
>
> --
> Jens Axboe
>
