On Tue 21-12-21 19:08:44, yukuai (C) wrote: > 在 2021/12/21 18:16, Jan Kara 写道: > > On Tue 21-12-21 11:21:33, Yu Kuai wrote: > > > Moving bfqq to it's parent bfqg is pointless. > > > > > > Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx> > > > > Did you notice that this is happening often enough that the check is worth > > it? Where do we do this? > > > > I noticed that this will happend when root group is offlined: > > bfq_pd_offline > bfq_put_async_queues > __bfq_put_async_bfqq > bfq_bfqq_move > > I'm not sure if there are other situations. I think bfq_bfqq_move() > is not happening often itself, thus the checking won't affect > performance. Yeah, OK, I was just wondering. I guess there's no harm in doing this check. Maybe add a comment that this can sometimes happen when dealing with the root cgroup. And then feel free to add: Reviewed-by: Jan Kara <jack@xxxxxxx> Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
