On Mon 22-03-21 15:42:27, Michal Hocko wrote:
[...]

Besides that the changelog doesn't really say anything about changed
user visible behavior change. Now if somebody decreases the GB huge pool
from the userspace the real effect on the freed up memory will be
postponed to some later time. That "later" is unpredictable as it
depends on WQ utilization. We definitely need some sort of
wait_for_inflight pages. One way to do that would be to have a dedicated
WQ and schedule a sync work item after the pool has been shrunk and wait
for that item.

Scratch that. It is not really clear from the patch context but after
looking at the resulting code set_max_huge_pages will use the blockable
update_and_free_page so we should be fine.

Sorry about the noise!
-- 
Michal Hocko
SUSE Labs