/*
* 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
static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *, unsigned int, unsigned short);
static void cfq_dispatch_sort(request_queue_t *, struct cfq_rq *);
static void cfq_put_cfqd(struct cfq_data *cfqd);
-static inline int cfq_pending_requests(struct cfq_data *cfqd);
#define process_sync(tsk) ((tsk)->flags & PF_SYNCWRITE)
return NULL;
}
+static inline int cfq_pending_requests(struct cfq_data *cfqd)
+{
+ return !list_empty(&cfqd->queue->queue_head) || cfqd->busy_queues;
+}
+
+/*
+ * scheduler run of queue, if there are requests pending and no one in the
+ * driver that will restart queueing
+ */
+static inline void cfq_schedule_dispatch(struct cfq_data *cfqd)
+{
+ if (!cfqd->rq_in_driver && cfq_pending_requests(cfqd))
+ kblockd_schedule_work(&cfqd->unplug_work);
+}
+
+static int cfq_queue_empty(request_queue_t *q)
+{
+ struct cfq_data *cfqd = q->elevator->elevator_data;
+
+ return !cfq_pending_requests(cfqd);
+}
+
/*
* Lifted from AS - choose which of crq1 and crq2 that is best served now.
* We choose the request that is closest to the head right now. Distance
return crq2;
if (crq2 == NULL)
return crq1;
- if (cfq_crq_requeued(crq1))
+
+ if (cfq_crq_requeued(crq1) && !cfq_crq_requeued(crq2))
+ return crq1;
+ 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;
- if (cfq_crq_requeued(crq2))
+ else if (cfq_crq_is_sync(crq2) && !cfq_crq_is_sync(crq1))
return crq2;
s1 = crq1->request->sector;
return 2 * (base_rq + base_rq * (CFQ_PRIO_LISTS - 1 - cfqq->ioprio));
}
-/*
- * scheduler run of queue, if there are requests pending and no one in the
- * driver that will restart queueing
- */
-static inline void cfq_schedule_dispatch(struct cfq_data *cfqd)
-{
- if (!cfqd->rq_in_driver && cfq_pending_requests(cfqd))
- kblockd_schedule_work(&cfqd->unplug_work);
-}
-
/*
* get next queue for service
*/
*/
if (!cfq_crq_in_driver(crq) &&
!cfq_cfqq_idle_window(cfqq) &&
+ !blk_barrier_rq(rq) &&
cfqd->rq_in_driver >= cfqd->cfq_max_depth)
return NULL;
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) {
/*
}
}
-static inline int cfq_pending_requests(struct cfq_data *cfqd)
-{
- return !list_empty(&cfqd->queue->queue_head) || cfqd->busy_queues;
-}
-
-static int cfq_queue_empty(request_queue_t *q)
-{
- struct cfq_data *cfqd = q->elevator->elevator_data;
-
- return !cfq_pending_requests(cfqd);
-}
-
static void cfq_completed_request(request_queue_t *q, struct request *rq)
{
struct cfq_rq *crq = RQ_DATA(rq);
{
#if 1
if ((cfq_cfqq_wait_request(cfqq) || cfq_cfqq_must_alloc(cfqq)) &&
- !cfq_cfqq_must_alloc_slice) {
+ !cfq_cfqq_must_alloc_slice(cfqq)) {
cfq_mark_cfqq_must_alloc_slice(cfqq);
return ELV_MQUEUE_MUST;
}
* only allow 1 ELV_MQUEUE_MUST per slice, otherwise we
* can quickly flood the queue with writes from a single task
*/
- if (rw == READ || !cfq_cfqq_must_alloc_slice) {
+ if (rw == READ || !cfq_cfqq_must_alloc_slice(cfqq)) {
cfq_mark_cfqq_must_alloc_slice(cfqq);
return ELV_MQUEUE_MUST;
}