On 7/17/21 6:33 AM, Oleksandr Natalenko wrote:

After mq-deadline learnt to deal with cgroups, the BLKCG_MAX_POLS value
became too small for all the elevators to be registered properly. The
following issue is seen:

calling  bfq_init+0x0/0x8b @ 1
blkcg_policy_register: BLKCG_MAX_POLS too small
initcall bfq_init+0x0/0x8b returned -28 after 507 usecs

and BFQ is non-functional.

Increase BLKCG_MAX_POLS to allow space for everyone

LGTM, just needs a:

Fixes: 08a9ad8bf607 ("block/mq-deadline: Add cgroup support")

in there too, I'll add it.

-- 
Jens Axboe