diff options
| -rw-r--r-- | block/bfq-iosched.c | 42 | ||||
| -rw-r--r-- | block/bfq-iosched.h | 18 | ||||
| -rw-r--r-- | block/bfq-wf2q.c | 23 |
3 files changed, 17 insertions, 66 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 71fadc7ebe0d..d5febdb0a6c0 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -970,48 +970,6 @@ reset_entity_pointer: void bfq_weights_tree_remove(struct bfq_data *bfqd, struct bfq_queue *bfqq) { - struct bfq_entity *entity = bfqq->entity.parent; - - for_each_entity(entity) { - struct bfq_sched_data *sd = entity->my_sched_data; - - if (sd->next_in_service || sd->in_service_entity) { - /* - * entity is still active, because either - * next_in_service or in_service_entity is not - * NULL (see the comments on the definition of - * next_in_service for details on why - * in_service_entity must be checked too). - * - * As a consequence, its parent entities are - * active as well, and thus this loop must - * stop here. - */ - break; - } - - /* - * The decrement of num_groups_with_pending_reqs is - * not performed immediately upon the deactivation of - * entity, but it is delayed to when it also happens - * that the first leaf descendant bfqq of entity gets - * all its pending requests completed. The following - * instructions perform this delayed decrement, if - * needed. See the comments on - * num_groups_with_pending_reqs for details. - */ - if (entity->in_groups_with_pending_reqs) { - entity->in_groups_with_pending_reqs = false; - bfqd->num_groups_with_pending_reqs--; - } - } - - /* - * Next function is invoked last, because it causes bfqq to be - * freed if the following holds: bfqq is not in service and - * has no dispatched request. DO NOT use bfqq after the next - * function invocation. - */ __bfq_weights_tree_remove(bfqd, bfqq, &bfqd->queue_weights_tree); } diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index 35b366eb702a..5bfb7fb3dc2b 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -492,27 +492,27 @@ struct bfq_data { struct rb_root_cached queue_weights_tree; /* - * Number of groups with at least one descendant process that + * Number of groups with at least one process that * has at least one request waiting for completion. Note that * this accounts for also requests already dispatched, but not * yet completed. Therefore this number of groups may differ * (be larger) than the number of active groups, as a group is * considered active only if its corresponding entity has - * descendant queues with at least one request queued. This + * queues with at least one request queued. This * number is used to decide whether a scenario is symmetric. * For a detailed explanation see comments on the computation * of the variable asymmetric_scenario in the function * bfq_better_to_idle(). * * However, it is hard to compute this number exactly, for - * groups with multiple descendant processes. Consider a group - * that is inactive, i.e., that has no descendant process with + * groups with multiple processes. Consider a group + * that is inactive, i.e., that has no process with * pending I/O inside BFQ queues. Then suppose that * num_groups_with_pending_reqs is still accounting for this - * group, because the group has descendant processes with some + * group, because the group has processes with some * I/O request still in flight. num_groups_with_pending_reqs * should be decremented when the in-flight request of the - * last descendant process is finally completed (assuming that + * last process is finally completed (assuming that * nothing else has changed for the group in the meantime, in * terms of composition of the group and active/inactive state of child * groups and processes). To accomplish this, an additional @@ -521,7 +521,7 @@ struct bfq_data { * we resort to the following tradeoff between simplicity and * accuracy: for an inactive group that is still counted in * num_groups_with_pending_reqs, we decrement - * num_groups_with_pending_reqs when the first descendant + * num_groups_with_pending_reqs when the first * process of the group remains with no request waiting for * completion. * @@ -529,12 +529,12 @@ struct bfq_data { * carefulness: to avoid multiple decrements, we flag a group, * more precisely an entity representing a group, as still * counted in num_groups_with_pending_reqs when it becomes - * inactive. Then, when the first descendant queue of the + * inactive. Then, when the first queue of the * entity remains with no request waiting for completion, * num_groups_with_pending_reqs is decremented, and this flag * is reset. After this flag is reset for the entity, * num_groups_with_pending_reqs won't be decremented any - * longer in case a new descendant queue of the entity remains + * longer in case a new queue of the entity remains * with no request waiting for completion. */ unsigned int num_groups_with_pending_reqs; diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c index 5549ccf09cd2..5e8224c96921 100644 --- a/block/bfq-wf2q.c +++ b/block/bfq-wf2q.c @@ -984,19 +984,6 @@ static void __bfq_activate_entity(struct bfq_entity *entity, entity->on_st_or_in_serv = true; } -#ifdef CONFIG_BFQ_GROUP_IOSCHED - if (!bfq_entity_to_bfqq(entity)) { /* bfq_group */ - struct bfq_group *bfqg = - container_of(entity, struct bfq_group, entity); - struct bfq_data *bfqd = bfqg->bfqd; - - if (!entity->in_groups_with_pending_reqs) { - entity->in_groups_with_pending_reqs = true; - bfqd->num_groups_with_pending_reqs++; - } - } -#endif - bfq_update_fin_time_enqueue(entity, st, backshifted); } @@ -1653,7 +1640,8 @@ void bfq_add_bfqq_in_groups_with_pending_reqs(struct bfq_queue *bfqq) if (!entity->in_groups_with_pending_reqs) { entity->in_groups_with_pending_reqs = true; #ifdef CONFIG_BFQ_GROUP_IOSCHED - bfqq_group(bfqq)->num_queues_with_pending_reqs++; + if (!(bfqq_group(bfqq)->num_queues_with_pending_reqs++)) + bfqq->bfqd->num_groups_with_pending_reqs++; #endif } } @@ -1665,7 +1653,8 @@ void bfq_del_bfqq_in_groups_with_pending_reqs(struct bfq_queue *bfqq) if (entity->in_groups_with_pending_reqs) { entity->in_groups_with_pending_reqs = false; #ifdef CONFIG_BFQ_GROUP_IOSCHED - bfqq_group(bfqq)->num_queues_with_pending_reqs--; + if (!(--bfqq_group(bfqq)->num_queues_with_pending_reqs)) + bfqq->bfqd->num_groups_with_pending_reqs--; #endif } } @@ -1694,6 +1683,10 @@ void bfq_del_bfqq_busy(struct bfq_queue *bfqq, bool expiration) if (!bfqq->dispatched) { bfq_del_bfqq_in_groups_with_pending_reqs(bfqq); + /* + * Next function is invoked last, because it causes bfqq to be + * freed. DO NOT use bfqq after the next function invocation. + */ bfq_weights_tree_remove(bfqd, bfqq); } } |