#define RQ_RB_ROOT(dd, rq) (&(dd)->sort_list[rq_data_dir((rq))])
+/*
+ * get the request after `rq' in sector-sorted order
+ */
+static inline struct request *
+deadline_latter_request(struct request *rq)
+{
+ struct rb_node *node = rb_next(&rq->rb_node);
+
+ if (node)
+ return rb_entry_rq(node);
+
+ return NULL;
+}
+
static void
deadline_add_rq_rb(struct deadline_data *dd, struct request *rq)
{
{
const int data_dir = rq_data_dir(rq);
- if (dd->next_rq[data_dir] == rq) {
- struct rb_node *rbnext = rb_next(&rq->rb_node);
-
- dd->next_rq[data_dir] = NULL;
- if (rbnext)
- dd->next_rq[data_dir] = rb_entry_rq(rbnext);
- }
+ if (dd->next_rq[data_dir] == rq)
+ dd->next_rq[data_dir] = deadline_latter_request(rq);
elv_rb_del(RQ_RB_ROOT(dd, rq), rq);
}
/*
* remove rq from rbtree and fifo.
*/
-static void deadline_remove_request(request_queue_t *q, struct request *rq)
+static void deadline_remove_request(struct request_queue *q, struct request *rq)
{
struct deadline_data *dd = q->elevator->elevator_data;
}
static int
-deadline_merge(request_queue_t *q, struct request **req, struct bio *bio)
+deadline_merge(struct request_queue *q, struct request **req, struct bio *bio)
{
struct deadline_data *dd = q->elevator->elevator_data;
struct request *__rq;
return ret;
}
-static void deadline_merged_request(request_queue_t *q, struct request *req,
- int type)
+static void deadline_merged_request(struct request_queue *q,
+ struct request *req, int type)
{
struct deadline_data *dd = q->elevator->elevator_data;
}
static void
-deadline_merged_requests(request_queue_t *q, struct request *req,
+deadline_merged_requests(struct request_queue *q, struct request *req,
struct request *next)
{
/*
static inline void
deadline_move_to_dispatch(struct deadline_data *dd, struct request *rq)
{
- request_queue_t *q = rq->q;
+ struct request_queue *q = rq->q;
deadline_remove_request(q, rq);
elv_dispatch_add_tail(q, rq);
deadline_move_request(struct deadline_data *dd, struct request *rq)
{
const int data_dir = rq_data_dir(rq);
- struct rb_node *rbnext = rb_next(&rq->rb_node);
dd->next_rq[READ] = NULL;
dd->next_rq[WRITE] = NULL;
+ dd->next_rq[data_dir] = deadline_latter_request(rq);
- if (rbnext)
- dd->next_rq[data_dir] = rb_entry_rq(rbnext);
-
dd->last_sector = rq->sector + rq->nr_sectors;
/*
* deadline_dispatch_requests selects the best request according to
* read/write expire, fifo_batch, etc
*/
-static int deadline_dispatch_requests(request_queue_t *q, int force)
+static int deadline_dispatch_requests(struct request_queue *q, int force)
{
struct deadline_data *dd = q->elevator->elevator_data;
const int reads = !list_empty(&dd->fifo_list[READ]);
/*
* we are not running a batch, find best request for selected data_dir
*/
- if (deadline_check_fifo(dd, data_dir)) {
- /* An expired request exists - satisfy it */
- dd->batching = 0;
+ if (deadline_check_fifo(dd, data_dir) || !dd->next_rq[data_dir]) {
+ /*
+ * A deadline has expired, the last request was in the other
+ * direction, or we have run out of higher-sectored requests.
+ * Start again from the request with the earliest expiry time.
+ */
rq = rq_entry_fifo(dd->fifo_list[data_dir].next);
-
- } else if (dd->next_rq[data_dir]) {
+ } else {
/*
* The last req was the same dir and we have a next request in
* sort order. No expired requests so continue on from here.
*/
rq = dd->next_rq[data_dir];
- } else {
- struct rb_node *node;
- /*
- * The last req was the other direction or we have run out of
- * higher-sectored requests. Go back to the lowest sectored
- * request (1 way elevator) and start a new batch.
- */
- dd->batching = 0;
- node = rb_first(&dd->sort_list[data_dir]);
- if (node)
- rq = rb_entry_rq(node);
}
+ dd->batching = 0;
+
dispatch_request:
/*
* rq is the selected appropriate request.
return 1;
}
-static int deadline_queue_empty(request_queue_t *q)
+static int deadline_queue_empty(struct request_queue *q)
{
struct deadline_data *dd = q->elevator->elevator_data;
/*
* initialize elevator private data (deadline_data).
*/
-static void *deadline_init_queue(request_queue_t *q)
+static void *deadline_init_queue(struct request_queue *q)
{
struct deadline_data *dd;
- dd = kmalloc_node(sizeof(*dd), GFP_KERNEL, q->node);
+ dd = kmalloc_node(sizeof(*dd), GFP_KERNEL | __GFP_ZERO, q->node);
if (!dd)
return NULL;
- memset(dd, 0, sizeof(*dd));
INIT_LIST_HEAD(&dd->fifo_list[READ]);
INIT_LIST_HEAD(&dd->fifo_list[WRITE]);
static int __init deadline_init(void)
{
- return elv_register(&iosched_deadline);
+ elv_register(&iosched_deadline);
+
+ return 0;
}
static void __exit deadline_exit(void)