| Message ID | 20220523131818.2798712-4-yukuai3@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | support concurrent sync io for bfq on a specail occasion | expand |
> Il giorno 23 mag 2022, alle ore 15:18, Yu Kuai <yukuai3@huawei.com> ha scritto: > > Now that root group is counted into 'num_groups_with_busy_queues', > 'num_groups_with_busy_queues > 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. This is ok. Yet, if the mistakes I found in the other two patches are actual errors, I wonder how these changes made it to pass your tests. Thanks, Paolo > > Signed-off-by: Yu Kuai <yukuai3@huawei.com> > Reviewed-by: Jan Kara <jack@suse.cz> > --- > block/bfq-iosched.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c > index 609b4e894684..142e1ca4600f 100644 > --- a/block/bfq-iosched.c > +++ b/block/bfq-iosched.c > @@ -812,7 +812,7 @@ 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 group 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. > @@ -844,7 +844,7 @@ 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_busy_queues > 0 > + || bfqd->num_groups_with_busy_queues > 1 > #endif > ; > } > -- > 2.31.1 >
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 609b4e894684..142e1ca4600f 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -812,7 +812,7 @@ 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 group 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. @@ -844,7 +844,7 @@ 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_busy_queues > 0 + || bfqd->num_groups_with_busy_queues > 1 #endif ; }