Re: [REGRESSION] bfq probe failed on 4.19-rc3

[Takashi Iwai]

On Tue, 11 Sep 2018 18:11:43 +0200,
Takashi Iwai wrote:
> 
> On Tue, 11 Sep 2018 18:09:44 +0200,
> Jens Axboe wrote:
> > 
> > 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?
> 
> 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.)

Takashi