diff options
| -rw-r--r-- | drivers/block/cfq-iosched.c | 31 |
1 files changed, 21 insertions, 10 deletions
diff --git a/drivers/block/cfq-iosched.c b/drivers/block/cfq-iosched.c index 2435a7c99b2..cd056e7e64e 100644 --- a/drivers/block/cfq-iosched.c +++ b/drivers/block/cfq-iosched.c @@ -47,7 +47,7 @@ static int cfq_slice_idle = HZ / 100; /* * disable queueing at the driver/hardware level */ -static int cfq_max_depth = 1; +static int cfq_max_depth = 2; /* * for the hash of cfqq inside the cfqd @@ -385,9 +385,15 @@ cfq_choose_req(struct cfq_data *cfqd, struct cfq_rq *crq1, struct cfq_rq *crq2) return crq2; if (crq2 == NULL) return crq1; - if (cfq_crq_requeued(crq1)) + + if (cfq_crq_requeued(crq1) && !cfq_crq_requeued(crq2)) return crq1; - if (cfq_crq_requeued(crq2)) + else if (cfq_crq_requeued(crq2) && !cfq_crq_requeued(crq1)) + return crq2; + + if (cfq_crq_is_sync(crq1) && !cfq_crq_is_sync(crq2)) + return crq1; + else if (cfq_crq_is_sync(crq2) && !cfq_crq_is_sync(crq1)) return crq2; s1 = crq1->request->sector; @@ -1769,18 +1775,23 @@ static void cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, struct cfq_rq *crq) { - const int sync = cfq_crq_is_sync(crq); + struct cfq_io_context *cic; cfqq->next_crq = cfq_choose_req(cfqd, cfqq->next_crq, crq); - if (sync) { - struct cfq_io_context *cic = crq->io_context; + /* + * we never wait for an async request and we don't allow preemption + * of an async request. so just return early + */ + if (!cfq_crq_is_sync(crq)) + return; - cfq_update_io_thinktime(cfqd, cic); - cfq_update_idle_window(cfqd, cfqq, cic); + cic = crq->io_context; - cic->last_queue = jiffies; - } + cfq_update_io_thinktime(cfqd, cic); + cfq_update_idle_window(cfqd, cfqq, cic); + + cic->last_queue = jiffies; if (cfqq == cfqd->active_queue) { /* |