| Message ID | 20220531140858.3324294-5-yukuai3@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | support concurrent sync io for bfq on a specail occasion | expand |
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@huawei.com> Looks good. Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> 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
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. * In particular, the last condition is always true if hierarchical * support or the cgroups interface are not enabled, thus no state * needs to be maintained in this case. @@ -852,7 +852,7 @@ static bool bfq_asymmetric_scenario(struct bfq_data *bfqd, return varied_queue_weights || multiple_classes_busy #ifdef CONFIG_BFQ_GROUP_IOSCHED - || bfqd->num_groups_with_pending_reqs > 0 + || bfqd->num_groups_with_pending_reqs > 1 #endif ; }
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@huawei.com> --- block/bfq-iosched.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)