03_blk_dispatch_queue_cfq.patch
Update cfq iosched to use generic dispatch queue
Signed-off-by: Tejun Heo <[email protected]>
cfq-iosched.c | 313 +++++++++++++---------------------------------------------
1 files changed, 72 insertions(+), 241 deletions(-)
Index: blk-fixes/drivers/block/cfq-iosched.c
===================================================================
--- blk-fixes.orig/drivers/block/cfq-iosched.c 2005-06-16 13:55:37.000000000 +0900
+++ blk-fixes/drivers/block/cfq-iosched.c 2005-06-16 13:55:38.000000000 +0900
@@ -83,7 +83,6 @@ static int cfq_max_depth = 1;
(node)->rb_left = NULL; \
} while (0)
#define RB_CLEAR_ROOT(root) ((root)->rb_node = NULL)
-#define ON_RB(node) ((node)->rb_color != RB_NONE)
#define rb_entry_crq(node) rb_entry((node), struct cfq_rq, rb_node)
#define rq_rb_key(rq) (rq)->sector
@@ -233,14 +232,11 @@ struct cfq_rq {
struct cfq_queue *cfq_queue;
struct cfq_io_context *io_context;
- unsigned in_flight : 1;
- unsigned accounted : 1;
unsigned is_sync : 1;
- unsigned requeued : 1;
};
static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *, unsigned int);
-static void cfq_dispatch_sort(request_queue_t *, struct cfq_rq *);
+static void cfq_dispatch_insert(request_queue_t *, struct cfq_rq *, int);
static void cfq_put_cfqd(struct cfq_data *cfqd);
#define process_sync(tsk) ((tsk)->flags & PF_SYNCWRITE)
@@ -253,14 +249,6 @@ static inline void cfq_del_crq_hash(stru
hlist_del_init(&crq->hash);
}
-static void cfq_remove_merge_hints(request_queue_t *q, struct cfq_rq *crq)
-{
- cfq_del_crq_hash(crq);
-
- if (q->last_merge == crq->request)
- q->last_merge = NULL;
-}
-
static inline void cfq_add_crq_hash(struct cfq_data *cfqd, struct cfq_rq *crq)
{
const int hash_idx = CFQ_MHASH_FN(rq_hash_key(crq->request));
@@ -305,10 +293,6 @@ cfq_choose_req(struct cfq_data *cfqd, st
return crq2;
if (crq2 == NULL)
return crq1;
- if (crq1->requeued)
- return crq1;
- if (crq2->requeued)
- return crq2;
s1 = crq1->request->sector;
s2 = crq2->request->sector;
@@ -375,10 +359,7 @@ cfq_find_next_crq(struct cfq_data *cfqd,
struct cfq_rq *crq_next = NULL, *crq_prev = NULL;
struct rb_node *rbnext, *rbprev;
- rbnext = NULL;
- if (ON_RB(&last->rb_node))
- rbnext = rb_next(&last->rb_node);
- if (!rbnext) {
+ if (!(rbnext = rb_next(&last->rb_node))) {
rbnext = rb_first(&cfqq->sort_list);
if (rbnext == &last->rb_node)
rbnext = NULL;
@@ -459,13 +440,13 @@ static void cfq_resort_rr_list(struct cf
* the pending list according to last request service
*/
static inline void
-cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq, int requeue)
+cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
BUG_ON(cfqq->on_rr);
cfqq->on_rr = 1;
cfqd->busy_queues++;
- cfq_resort_rr_list(cfqq, requeue);
+ cfq_resort_rr_list(cfqq, 0);
}
static inline void
@@ -485,22 +466,20 @@ cfq_del_cfqq_rr(struct cfq_data *cfqd, s
static inline void cfq_del_crq_rb(struct cfq_rq *crq)
{
struct cfq_queue *cfqq = crq->cfq_queue;
+ struct cfq_data *cfqd = cfqq->cfqd;
+ const int sync = crq->is_sync;
- if (ON_RB(&crq->rb_node)) {
- struct cfq_data *cfqd = cfqq->cfqd;
- const int sync = crq->is_sync;
+ BUG_ON(!cfqq->queued[sync]);
+ cfqq->queued[sync]--;
- BUG_ON(!cfqq->queued[sync]);
- cfqq->queued[sync]--;
+ cfq_update_next_crq(crq);
- cfq_update_next_crq(crq);
+ rb_erase(&crq->rb_node, &cfqq->sort_list);
+ RB_CLEAR_COLOR(&crq->rb_node);
- rb_erase(&crq->rb_node, &cfqq->sort_list);
- RB_CLEAR_COLOR(&crq->rb_node);
+ if (cfqq->on_rr && RB_EMPTY(&cfqq->sort_list))
+ cfq_del_cfqq_rr(cfqd, cfqq);
- if (cfqq->on_rr && RB_EMPTY(&cfqq->sort_list))
- cfq_del_cfqq_rr(cfqd, cfqq);
- }
}
static struct cfq_rq *
@@ -541,12 +520,12 @@ static void cfq_add_crq_rb(struct cfq_rq
* if that happens, put the alias on the dispatch list
*/
while ((__alias = __cfq_add_crq_rb(crq)) != NULL)
- cfq_dispatch_sort(cfqd->queue, __alias);
+ cfq_dispatch_insert(cfqd->queue, __alias, 1);
rb_insert_color(&crq->rb_node, &cfqq->sort_list);
if (!cfqq->on_rr)
- cfq_add_cfqq_rr(cfqd, cfqq, crq->requeued);
+ cfq_add_cfqq_rr(cfqd, cfqq);
/*
* check if this request is a better next-serve candidate
@@ -557,10 +536,8 @@ static void cfq_add_crq_rb(struct cfq_rq
static inline void
cfq_reposition_crq_rb(struct cfq_queue *cfqq, struct cfq_rq *crq)
{
- if (ON_RB(&crq->rb_node)) {
- rb_erase(&crq->rb_node, &cfqq->sort_list);
- cfqq->queued[crq->is_sync]--;
- }
+ rb_erase(&crq->rb_node, &cfqq->sort_list);
+ cfqq->queued[crq->is_sync]--;
cfq_add_crq_rb(crq);
}
@@ -590,47 +567,28 @@ out:
return NULL;
}
-static void cfq_deactivate_request(request_queue_t *q, struct request *rq)
+static void cfq_activate_request(request_queue_t *q, struct request *rq)
{
struct cfq_data *cfqd = q->elevator->elevator_data;
- struct cfq_rq *crq = RQ_DATA(rq);
-
- if (crq) {
- struct cfq_queue *cfqq = crq->cfq_queue;
- if (crq->accounted) {
- crq->accounted = 0;
- WARN_ON(!cfqd->rq_in_driver);
- cfqd->rq_in_driver--;
- }
- if (crq->in_flight) {
- crq->in_flight = 0;
- WARN_ON(!cfqq->in_flight);
- cfqq->in_flight--;
- }
- crq->requeued = 1;
- }
+ cfqd->rq_in_driver++;
}
-/*
- * make sure the service time gets corrected on reissue of this request
- */
-static void cfq_requeue_request(request_queue_t *q, struct request *rq)
+static void cfq_deactivate_request(request_queue_t *q, struct request *rq)
{
- cfq_deactivate_request(q, rq);
- list_add(&rq->queuelist, &q->queue_head);
+ struct cfq_data *cfqd = q->elevator->elevator_data;
+
+ WARN_ON(!cfqd->rq_in_driver);
+ cfqd->rq_in_driver--;
}
-static void cfq_remove_request(request_queue_t *q, struct request *rq)
+static void cfq_remove_request(struct request *rq)
{
struct cfq_rq *crq = RQ_DATA(rq);
- if (crq) {
- list_del_init(&rq->queuelist);
- cfq_del_crq_rb(crq);
- cfq_remove_merge_hints(q, crq);
-
- }
+ list_del_init(&rq->queuelist);
+ cfq_del_crq_rb(crq);
+ cfq_del_crq_hash(crq);
}
static int
@@ -674,7 +632,7 @@ static void cfq_merged_request(request_q
cfq_del_crq_hash(crq);
cfq_add_crq_hash(cfqd, crq);
- if (ON_RB(&crq->rb_node) && (rq_rb_key(req) != crq->rb_key)) {
+ if (rq_rb_key(req) != crq->rb_key) {
struct cfq_queue *cfqq = crq->cfq_queue;
cfq_update_next_crq(crq);
@@ -697,7 +655,7 @@ cfq_merged_requests(request_queue_t *q,
time_before(next->start_time, rq->start_time))
list_move(&rq->queuelist, &next->queuelist);
- cfq_remove_request(q, next);
+ cfq_remove_request(next);
}
static inline void
@@ -878,52 +836,16 @@ static int cfq_arm_slice_timer(struct cf
return 1;
}
-/*
- * we dispatch cfqd->cfq_quantum requests in total from the rr_list queues,
- * this function sector sorts the selected request to minimize seeks. we start
- * at cfqd->last_sector, not 0.
- */
-static void cfq_dispatch_sort(request_queue_t *q, struct cfq_rq *crq)
+static void cfq_dispatch_insert(request_queue_t *q, struct cfq_rq *crq,
+ int force)
{
struct cfq_data *cfqd = q->elevator->elevator_data;
struct cfq_queue *cfqq = crq->cfq_queue;
- struct list_head *head = &q->queue_head, *entry = head;
- struct request *__rq;
- sector_t last;
-
- list_del(&crq->request->queuelist);
-
- last = cfqd->last_sector;
- list_for_each_entry_reverse(__rq, head, queuelist) {
- struct cfq_rq *__crq = RQ_DATA(__rq);
-
- if (blk_barrier_rq(__rq))
- break;
- if (!blk_fs_request(__rq))
- break;
- if (__crq->requeued)
- break;
-
- if (__rq->sector <= crq->request->sector)
- break;
- if (__rq->sector > last && crq->request->sector < last) {
- last = crq->request->sector + crq->request->nr_sectors;
- break;
- }
- entry = &__rq->queuelist;
- }
-
- cfqd->last_sector = last;
cfqq->next_crq = cfq_find_next_crq(cfqd, cfqq, crq);
-
- cfq_del_crq_rb(crq);
- cfq_remove_merge_hints(q, crq);
-
- crq->in_flight = 1;
- crq->requeued = 0;
+ cfq_remove_request(crq->request);
cfqq->in_flight++;
- list_add_tail(&crq->request->queuelist, entry);
+ elv_dispatch_insert(q, crq->request, force);
}
/*
@@ -1020,7 +942,7 @@ keep_queue:
static int
__cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq,
- int max_dispatch)
+ int max_dispatch, int force)
{
int dispatched = 0;
@@ -1038,7 +960,7 @@ __cfq_dispatch_requests(struct cfq_data
/*
* finally, insert request into driver dispatch list
*/
- cfq_dispatch_sort(cfqd->queue, crq);
+ cfq_dispatch_insert(cfqd->queue, crq, force);
cfqd->dispatch_slice++;
dispatched++;
@@ -1073,7 +995,7 @@ __cfq_dispatch_requests(struct cfq_data
}
static int
-cfq_dispatch_requests(request_queue_t *q, int max_dispatch, int force)
+cfq_dispatch_requests(request_queue_t *q, int force)
{
struct cfq_data *cfqd = q->elevator->elevator_data;
struct cfq_queue *cfqq;
@@ -1083,96 +1005,31 @@ cfq_dispatch_requests(request_queue_t *q
cfqq = cfq_select_queue(cfqd, force);
if (cfqq) {
+ int max_dispatch;
+
+ /*
+ * if idle window is disabled, allow queue buildup
+ */
+ if (!cfqq->idle_window &&
+ cfqd->rq_in_driver >= cfqd->cfq_max_depth)
+ return 0;
+
cfqq->wait_request = 0;
cfqq->must_dispatch = 0;
del_timer(&cfqd->idle_slice_timer);
- if (cfq_class_idle(cfqq))
- max_dispatch = 1;
+ if (force)
+ max_dispatch = INT_MAX;
+ else
+ max_dispatch =
+ cfq_class_idle(cfqq) ? 1 : cfqd->cfq_quantum;
- return __cfq_dispatch_requests(cfqd, cfqq, max_dispatch);
+ return __cfq_dispatch_requests(cfqd, cfqq, max_dispatch, force);
}
return 0;
}
-static inline void cfq_account_dispatch(struct cfq_rq *crq)
-{
- struct cfq_queue *cfqq = crq->cfq_queue;
- struct cfq_data *cfqd = cfqq->cfqd;
-
- if (unlikely(!blk_fs_request(crq->request)))
- return;
-
- /*
- * accounted bit is necessary since some drivers will call
- * elv_next_request() many times for the same request (eg ide)
- */
- if (crq->accounted)
- return;
-
- crq->accounted = 1;
- cfqd->rq_in_driver++;
-}
-
-static inline void
-cfq_account_completion(struct cfq_queue *cfqq, struct cfq_rq *crq)
-{
- struct cfq_data *cfqd = cfqq->cfqd;
- unsigned long now;
-
- if (!crq->accounted)
- return;
-
- now = jiffies;
-
- WARN_ON(!cfqd->rq_in_driver);
- cfqd->rq_in_driver--;
-
- if (!cfq_class_idle(cfqq))
- cfqd->last_end_request = now;
-
- if (!cfqq->in_flight && cfqq->on_rr) {
- cfqq->service_last = now;
- cfq_resort_rr_list(cfqq, 0);
- }
-
- if (crq->is_sync)
- crq->io_context->last_end_request = now;
-}
-
-static struct request *cfq_next_request(request_queue_t *q)
-{
- struct cfq_data *cfqd = q->elevator->elevator_data;
- struct request *rq;
-
- if (!list_empty(&q->queue_head)) {
- struct cfq_rq *crq;
-dispatch:
- rq = list_entry_rq(q->queue_head.next);
-
- crq = RQ_DATA(rq);
- if (crq) {
- /*
- * if idle window is disabled, allow queue buildup
- */
- if (!crq->in_flight && !crq->cfq_queue->idle_window &&
- cfqd->rq_in_driver >= cfqd->cfq_max_depth)
- return NULL;
-
- cfq_remove_merge_hints(q, crq);
- cfq_account_dispatch(crq);
- }
-
- return rq;
- }
-
- if (cfq_dispatch_requests(q, cfqd->cfq_quantum, 0))
- goto dispatch;
-
- return NULL;
-}
-
/*
* task holds one reference to the queue, dropped when task exits. each crq
* in-flight on this queue also holds a reference, dropped when crq is freed.
@@ -1675,8 +1532,9 @@ cfq_crq_enqueued(struct cfq_data *cfqd,
}
}
-static void cfq_enqueue(struct cfq_data *cfqd, struct request *rq)
+static void cfq_insert_request(request_queue_t *q, struct request *rq)
{
+ struct cfq_data *cfqd = q->elevator->elevator_data;
struct cfq_rq *crq = RQ_DATA(rq);
struct cfq_queue *cfqq = crq->cfq_queue;
@@ -1696,38 +1554,6 @@ static void cfq_enqueue(struct cfq_data
cfq_crq_enqueued(cfqd, cfqq, crq);
}
-static void
-cfq_insert_request(request_queue_t *q, struct request *rq, int where)
-{
- struct cfq_data *cfqd = q->elevator->elevator_data;
-
- switch (where) {
- case ELEVATOR_INSERT_BACK:
- while (cfq_dispatch_requests(q, INT_MAX, 1))
- ;
- list_add_tail(&rq->queuelist, &q->queue_head);
- /*
- * If we were idling with pending requests on
- * inactive cfqqs, force dispatching will
- * remove the idle timer and the queue won't
- * be kicked by __make_request() afterward.
- * Kick it here.
- */
- kblockd_schedule_work(&cfqd->unplug_work);
- break;
- case ELEVATOR_INSERT_FRONT:
- list_add(&rq->queuelist, &q->queue_head);
- break;
- case ELEVATOR_INSERT_SORT:
- BUG_ON(!blk_fs_request(rq));
- cfq_enqueue(cfqd, rq);
- break;
- default:
- printk("%s: bad insert point %d\n", __FUNCTION__,where);
- return;
- }
-}
-
static inline int cfq_pending_requests(struct cfq_data *cfqd)
{
return !list_empty(&cfqd->queue->queue_head) || cfqd->busy_queues;
@@ -1743,19 +1569,27 @@ static int cfq_queue_empty(request_queue
static void cfq_completed_request(request_queue_t *q, struct request *rq)
{
struct cfq_rq *crq = RQ_DATA(rq);
- struct cfq_queue *cfqq;
+ struct cfq_queue *cfqq = crq->cfq_queue;
+ struct cfq_data *cfqd = cfqq->cfqd;
+ unsigned long now;
- if (unlikely(!blk_fs_request(rq)))
- return;
+ now = jiffies;
- cfqq = crq->cfq_queue;
+ WARN_ON(!cfqd->rq_in_driver);
+ WARN_ON(!cfqq->in_flight);
+ cfqd->rq_in_driver--;
+ cfqq->in_flight--;
- if (crq->in_flight) {
- WARN_ON(!cfqq->in_flight);
- cfqq->in_flight--;
+ if (!cfq_class_idle(cfqq))
+ cfqd->last_end_request = now;
+
+ if (!cfqq->in_flight && cfqq->on_rr) {
+ cfqq->service_last = now;
+ cfq_resort_rr_list(cfqq, 0);
}
- cfq_account_completion(cfqq, crq);
+ if (crq->is_sync)
+ crq->io_context->last_end_request = now;
}
static struct request *
@@ -1981,9 +1815,7 @@ cfq_set_request(request_queue_t *q, stru
INIT_HLIST_NODE(&crq->hash);
crq->cfq_queue = cfqq;
crq->io_context = cic;
- crq->in_flight = crq->accounted = 0;
crq->is_sync = (rw == READ || process_sync(current));
- crq->requeued = 0;
rq->elevator_private = crq;
return 0;
}
@@ -2426,10 +2258,9 @@ static struct elevator_type iosched_cfq
.elevator_merge_fn = cfq_merge,
.elevator_merged_fn = cfq_merged_request,
.elevator_merge_req_fn = cfq_merged_requests,
- .elevator_next_req_fn = cfq_next_request,
+ .elevator_dispatch_fn = cfq_dispatch_requests,
.elevator_add_req_fn = cfq_insert_request,
- .elevator_remove_req_fn = cfq_remove_request,
- .elevator_requeue_req_fn = cfq_requeue_request,
+ .elevator_activate_req_fn = cfq_activate_request,
.elevator_deactivate_req_fn = cfq_deactivate_request,
.elevator_queue_empty_fn = cfq_queue_empty,
.elevator_completed_req_fn = cfq_completed_request,
-
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