On 9/11/18 10:16 AM, Takashi Iwai wrote:

On Tue, 11 Sep 2018 18:11:43 +0200,
Takashi Iwai wrote:

quoted

On Tue, 11 Sep 2018 18:09:44 +0200,
Jens Axboe wrote:

quoted

On 9/11/18 10:03 AM, Takashi Iwai wrote:

quoted

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?

IIRC, 4.18 worked fine.  Let me see whether I have a backup...

Confirmed that 4.18 worked.  It's also with CONFIG_IOSCHED_BFQ=y and
CONFIG_BFQ_GROUP_IOSCHED=y.

And, 4.19-rc3 with CONFIG_BFQ_GROUP_IOSCHED=n seems working, too (as
expected from the error above).


(BTW I'll have to leave from this machine now.  For any further
 inquiry, I'll check tomorrow, sorry.)

Very odd. Maybe try without CONFIG_BLK_CGROUP_IOLATENCY being set?
I'll try and reproduce it here.

-- 
Jens Axboe