Root group is not counted into 'num_groups_with_pending_reqs' because 'entity->parent' is set to NULL for child entities, thus for_each_entity() can't access root group. This patch set root_group's entity to 'entity->parent' for child entities, It's okay with previous patches handle the case that for_each_entity() access root group. Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx> --- block/bfq-cgroup.c | 2 +- block/bfq-iosched.h | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index 24a5c5329bcd..9c36deda4ed4 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -436,7 +436,7 @@ void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg) */ bfqg_and_blkg_get(bfqg); } - entity->parent = bfqg->my_entity; /* NULL for root group */ + entity->parent = &bfqg->entity; entity->sched_data = &bfqg->sched_data; } diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index ef875b8046e5..515eb2604a37 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -1021,13 +1021,14 @@ extern struct blkcg_policy blkcg_policy_bfq; /* - interface of the internal hierarchical B-WF2Q+ scheduler - */ #ifdef CONFIG_BFQ_GROUP_IOSCHED -/* stop at one of the child entities of the root group */ +/* stop at root group */ #define for_each_entity(entity) \ for (; entity ; entity = entity->parent) #define is_root_entity(entity) \ (entity->sched_data == NULL) +/* stop at one of the child entities of the root group */ #define for_each_entity_not_root(entity) \ for (; entity && !is_root_entity(entity); entity = entity->parent) -- 2.31.1