diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 93ba54605eda98c9c62657e3e461526c34a31a61..5d2047b93eb5373294fe5d344703a34a1e8debc8 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -133,6 +133,7 @@ struct cfq_data { mempool_t *crq_pool; int rq_in_driver; + int hw_tag; /* * schedule slice state info @@ -664,6 +665,15 @@ static void cfq_activate_request(request_queue_t *q, struct request *rq) struct cfq_data *cfqd = q->elevator->elevator_data; cfqd->rq_in_driver++; + + /* + * If the depth is larger 1, it really could be queueing. But lets + * make the mark a little higher - idling could still be good for + * low queueing, and a low queueing number could also just indicate + * a SCSI mid layer like behaviour where limit+1 is often seen. + */ + if (!cfqd->hw_tag && cfqd->rq_in_driver > 4) + cfqd->hw_tag = 1; } static void cfq_deactivate_request(request_queue_t *q, struct request *rq) @@ -1465,7 +1475,8 @@ cfq_get_queue(struct cfq_data *cfqd, unsigned int key, struct task_struct *tsk, * set ->slice_left to allow preemption for a new process */ cfqq->slice_left = 2 * cfqd->cfq_slice_idle; - cfq_mark_cfqq_idle_window(cfqq); + if (!cfqd->hw_tag) + cfq_mark_cfqq_idle_window(cfqq); cfq_mark_cfqq_prio_changed(cfqq); cfq_init_prio_data(cfqq); } @@ -1656,7 +1667,7 @@ cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, { int enable_idle = cfq_cfqq_idle_window(cfqq); - if (!cic->ioc->task || !cfqd->cfq_slice_idle) + if (!cic->ioc->task || !cfqd->cfq_slice_idle || cfqd->hw_tag) enable_idle = 0; else if (sample_valid(cic->ttime_samples)) { if (cic->ttime_mean > cfqd->cfq_slice_idle)