Jens Axboe <axboe@xxxxxxxxx> writes:
> On 9/11/18 10:48 AM, Jeff Moyer wrote:
>> Jens Axboe <axboe@xxxxxxxxx> writes:
>>
>>> On 9/11/18 10:03 AM, Takashi Iwai wrote:
>>>> Hi,
>>>>
>>>> I noticed that bfq doesn't appear in the I/O scheduler list on
>>>> 4.19-rc3. It seems that blkcg_policy_register() at the beginning of
>>>> bfq_init() returns -ENOSPC, hence the probe aborts silently.
>>>>
>>>> Is this already addressed?
>>>
>>> Haven't heard about this one before. What kernel did you last use that
>>> worked?
>>
>> I'm guessing you just need to update the maximum number of policies:
>>
>> /*
>> * Maximum number of blkcg policies allowed to be registered concurrently.
>> * Defined here to simplify include dependency.
>> */
>> #define BLKCG_MAX_POLS 3
>
> That is my guess too, hence the suggestion to try and disable the
> iolatency policy. Just tried here without, and it works, rebooting
> with to verify that we're running out of policy slots.
Functions calling this function: blkcg_policy_register
File Function Line
0 block/bfq-iosched.c bfq_init 5675 ret =
blkcg_policy_register(&blkcg_pol
icy_bfq);
1 block/blk-iolatency.c iolatency_init 946 return
blkcg_policy_register(&blkcg_pol
icy_iolatency);
2 block/blk-throttle.c throtl_init 2511 return
blkcg_policy_register(&blkcg_pol
icy_throtl);
3 block/cfq-iosched.c cfq_init 4869 ret =
blkcg_policy_register(&blkcg_pol
icy_cfq);
And then there were 4...
-Jeff
