'entity->sched_data' is set to parent group's sched_data, thus it's NULL for root group. And for_each_entity() is used widely to access 'entity->sched_data', thus aplly news apis if root group is not expected. The case that root group is expected will be handled in next patch. Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx> --- block/bfq-iosched.c | 2 +- block/bfq-iosched.h | 22 ++++++++-------------- block/bfq-wf2q.c | 10 +++++----- 3 files changed, 14 insertions(+), 20 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 1ce1a99a7160..3262d062e21f 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -4273,7 +4273,7 @@ void bfq_bfqq_expire(struct bfq_data *bfqd, * service with the same budget. */ entity = entity->parent; - for_each_entity(entity) + for_each_entity_not_root(entity) entity->service = 0; } diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index f5afc80ff11c..ef875b8046e5 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -1021,25 +1021,22 @@ extern struct blkcg_policy blkcg_policy_bfq; /* - interface of the internal hierarchical B-WF2Q+ scheduler - */ #ifdef CONFIG_BFQ_GROUP_IOSCHED -/* both next loops stop at one of the child entities of the root group */ +/* stop at one of the child entities of the root group */ #define for_each_entity(entity) \ for (; entity ; entity = entity->parent) -/* - * For each iteration, compute parent in advance, so as to be safe if - * entity is deallocated during the iteration. Such a deallocation may - * happen as a consequence of a bfq_put_queue that frees the bfq_queue - * containing entity. - */ -#define for_each_entity_safe(entity, parent) \ - for (; entity && ({ parent = entity->parent; 1; }); entity = parent) - #define is_root_entity(entity) \ (entity->sched_data == NULL) #define for_each_entity_not_root(entity) \ for (; entity && !is_root_entity(entity); entity = entity->parent) +/* + * For each iteration, compute parent in advance, so as to be safe if + * entity is deallocated during the iteration. Such a deallocation may + * happen as a consequence of a bfq_put_queue that frees the bfq_queue + * containing entity. + */ #define for_each_entity_not_root_safe(entity, parent) \ for (; entity && !is_root_entity(entity) && \ ({ parent = entity->parent; 1; }); entity = parent) @@ -1047,16 +1044,13 @@ extern struct blkcg_policy blkcg_policy_bfq; #define is_root_entity(entity) (false) /* - * Next four macros are fake loops when cgroups support is not + * Next three macros are fake loops when cgroups support is not * enabled. I fact, in such a case, there is only one level to go up * (to reach the root group). */ #define for_each_entity(entity) \ for (; entity ; entity = NULL) -#define for_each_entity_safe(entity, parent) \ - for (parent = NULL; entity ; entity = parent) - #define for_each_entity_not_root(entity) \ for (; entity ; entity = NULL) diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c index b74cc0da118e..67e32481e455 100644 --- a/block/bfq-wf2q.c +++ b/block/bfq-wf2q.c @@ -830,7 +830,7 @@ void bfq_bfqq_served(struct bfq_queue *bfqq, int served) bfqq->service_from_wr += served; bfqq->service_from_backlogged += served; - for_each_entity(entity) { + for_each_entity_not_root(entity) { st = bfq_entity_service_tree(entity); entity->service += served; @@ -1216,7 +1216,7 @@ static void bfq_deactivate_entity(struct bfq_entity *entity, struct bfq_sched_data *sd; struct bfq_entity *parent = NULL; - for_each_entity_safe(entity, parent) { + for_each_entity_not_root_safe(entity, parent) { sd = entity->sched_data; if (!__bfq_deactivate_entity(entity, ins_into_idle_tree)) { @@ -1285,7 +1285,7 @@ static void bfq_deactivate_entity(struct bfq_entity *entity, * is not the case. */ entity = parent; - for_each_entity(entity) { + for_each_entity_not_root(entity) { /* * Invoke __bfq_requeue_entity on entity, even if * already active, to requeue/reposition it in the @@ -1585,7 +1585,7 @@ struct bfq_queue *bfq_get_next_queue(struct bfq_data *bfqd) * We can finally update all next-to-serve entities along the * path from the leaf entity just set in service to the root. */ - for_each_entity(entity) { + for_each_entity_not_root(entity) { struct bfq_sched_data *sd = entity->sched_data; if (!bfq_update_next_in_service(sd, NULL, false)) @@ -1612,7 +1612,7 @@ bool __bfq_bfqd_reset_in_service(struct bfq_data *bfqd) * execute the final step: reset in_service_entity along the * path from entity to the root. */ - for_each_entity(entity) + for_each_entity_not_root(entity) entity->sched_data->in_service_entity = NULL; /* -- 2.31.1