diff options
Diffstat (limited to 'block/bfq-iosched.c')
| -rw-r--r-- | block/bfq-iosched.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 05944cbaa..cf487f926 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -1330,9 +1330,11 @@ static struct bfq_queue *bfq_find_close_cooperator(struct bfq_data *bfqd, struct bfq_queue *bfqq; /* - * We should notice if some of the queues are cooperating, e.g. - * working closely on the same area of the disk. In that case, - * we can group them together and don't waste time idling. + * We shall notice if some of the queues are cooperating, + * e.g., working closely on the same area of the device. In + * that case, we can group them together and: 1) don't waste + * time idling, and 2) serve the union of their requests in + * the best possible order for throughput. */ bfqq = bfqq_find_close(bfqd, cur_bfqq, sector); if (!bfqq || bfqq == cur_bfqq) @@ -1405,9 +1407,6 @@ bfq_setup_merge(struct bfq_queue *bfqq, struct bfq_queue *new_bfqq) static bool bfq_may_be_close_cooperator(struct bfq_queue *bfqq, struct bfq_queue *new_bfqq) { - if (WARN_ON(bfqq->entity.parent != new_bfqq->entity.parent)) - return false; - if (bfq_class_idle(bfqq) || bfq_class_idle(new_bfqq) || (bfqq->ioprio_class != new_bfqq->ioprio_class)) return false; @@ -1466,6 +1465,7 @@ bfq_setup_cooperator(struct bfq_data *bfqd, struct bfq_queue *bfqq, goto check_scheduled; if (bfq_rq_close_to_sector(io_struct, request, bfqd->last_position) && + bfqq->entity.parent == in_service_bfqq->entity.parent && bfq_may_be_close_cooperator(bfqq, in_service_bfqq)) { new_bfqq = bfq_setup_merge(bfqq, in_service_bfqq); if (new_bfqq) @@ -1479,6 +1479,9 @@ bfq_setup_cooperator(struct bfq_data *bfqd, struct bfq_queue *bfqq, check_scheduled: new_bfqq = bfq_find_close_cooperator(bfqd, bfqq, bfq_io_struct_pos(io_struct, request)); + + BUG_ON(new_bfqq && bfqq->entity.parent != new_bfqq->entity.parent); + if (new_bfqq && likely(new_bfqq != &bfqd->oom_bfqq) && bfq_may_be_close_cooperator(bfqq, new_bfqq)) return bfq_setup_merge(bfqq, new_bfqq); |