From: Chunguang Xu <brookxu@xxxxxxxxxxx> Under better_fairness, if higher priority queue is waiting for service，disable queue idle, so that a schedule can be invoked in time. In addition to CLASS_IDLE, other queues allow idle, so that we can better control buffer IO too. Signed-off-by: Chunguang Xu <brookxu@xxxxxxxxxxx> --- block/bfq-iosched.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index be5b1e3..5aa9c2c 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -4307,6 +4307,14 @@ static bool bfq_better_to_idle(struct bfq_queue *bfqq) return true; /* + * In better_fairness mode, we also put emphasis on Qos. The main + * purpose of allowing idle here is to ensure better isolation + * of Buffer IO. + */ + if (unlikely(bfqd->better_fairness)) + return !(bfqd->bfq_slice_idle == 0 || bfq_class_idle(bfqq)); + + /* * Idling is performed only if slice_idle > 0. In addition, we * do not idle if * (a) bfqq is async @@ -4318,6 +4326,9 @@ static bool bfq_better_to_idle(struct bfq_queue *bfqq) bfq_class_idle(bfqq)) return false; + if (bfq_may_expire_in_serv_for_prio(&bfqq->entity)) + return false; + idling_boosts_thr_with_no_issue = idling_boosts_thr_without_issues(bfqd, bfqq); -- 1.8.3.1
