Currently, bfqg will be counted into 'num_groups_with_pending_reqs'
once it's child cgroup is activated, even if the group doesn't have
any pending requests itself.
For example, if we issue sync io in cgroup /root/c1/c2, root, c1 and c2
will all be counted into 'num_groups_with_pending_reqs', which makes it
impossible to handle requests concurrently.
This patch doesn't count the group that doesn't have any pending
requests while it's child group has pending requests.
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
block/bfq-wf2q.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)
diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c
index 138a2950b841..db066ae35a71 100644
--- a/block/bfq-wf2q.c
+++ b/block/bfq-wf2q.c
@@ -1123,13 +1123,7 @@ static void bfq_activate_requeue_entity(struct bfq_entity *entity,
bool non_blocking_wait_rq,
bool requeue, bool expiration)
{
- for_each_entity(entity) {
- bfq_update_groups_with_pending_reqs(entity);
-
- /* root group is not in service tree */
- if (is_root_entity(entity))
- break;
-
+ for_each_entity_not_root(entity) {
__bfq_activate_requeue_entity(entity, non_blocking_wait_rq);
if (!bfq_update_next_in_service(entity->sched_data, entity,
@@ -1640,6 +1634,7 @@ void bfq_activate_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq)
{
struct bfq_entity *entity = &bfqq->entity;
+ bfq_update_groups_with_pending_reqs(bfqq->entity.parent);
bfq_activate_requeue_entity(entity, bfq_bfqq_non_blocking_wait_rq(bfqq),
false, false);
bfq_clear_bfqq_non_blocking_wait_rq(bfqq);
--
2.31.1
