On Tue 31-05-22 22:08:58, Yu Kuai wrote: > Now that root group is counted into 'num_groups_with_pending_reqs', > 'num_groups_with_pending_reqs > 0' is always true in > bfq_asymmetric_scenario(). Thus change the condition to '> 1'. > > On the other hand, this change can enable concurrent sync io if only > one group is activated. > > Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx> Looks good. Feel free to add: Reviewed-by: Jan Kara <jack@xxxxxxx> Just one language fixup below: > diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c > index 03b04892440c..d4aa8421968d 100644 > --- a/block/bfq-iosched.c > +++ b/block/bfq-iosched.c > @@ -820,7 +820,7 @@ bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq) > * much easier to maintain the needed state: > * 1) all active queues have the same weight, > * 2) all active queues belong to the same I/O-priority class, > - * 3) there are no active groups. > + * 3) there are one active groups at most. ^^^ "there is at most one active group" Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR