diff options
| -rw-r--r-- | block/cfq-iosched.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 47d6aaca0c5..418da9a49bb 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -2257,6 +2257,8 @@ static void cfq_insert_request(struct request_queue *q, struct request *rq) */ static void cfq_update_hw_tag(struct cfq_data *cfqd) { + struct cfq_queue *cfqq = cfqd->active_queue; + if (rq_in_driver(cfqd) > cfqd->rq_in_driver_peak) cfqd->rq_in_driver_peak = rq_in_driver(cfqd); @@ -2264,6 +2266,16 @@ static void cfq_update_hw_tag(struct cfq_data *cfqd) rq_in_driver(cfqd) <= CFQ_HW_QUEUE_MIN) return; + /* + * If active queue hasn't enough requests and can idle, cfq might not + * dispatch sufficient requests to hardware. Don't zero hw_tag in this + * case + */ + if (cfqq && cfq_cfqq_idle_window(cfqq) && + cfqq->dispatched + cfqq->queued[0] + cfqq->queued[1] < + CFQ_HW_QUEUE_MIN && rq_in_driver(cfqd) < CFQ_HW_QUEUE_MIN) + return; + if (cfqd->hw_tag_samples++ < 50) return; |