diff options
| -rw-r--r-- | block/noop-iosched.c | 85 |
1 files changed, 79 insertions, 6 deletions
diff --git a/block/noop-iosched.c b/block/noop-iosched.c index e54f006..f370e4a 100644 --- a/block/noop-iosched.c +++ b/block/noop-iosched.c @@ -7,21 +7,94 @@ #include <linux/module.h> #include <linux/init.h> -static void elevator_noop_add_request(request_queue_t *q, struct request *rq) +struct noop_data { + struct list_head queue; +}; + +static void noop_merged_requests(request_queue_t *q, struct request *rq, + struct request *next) +{ + list_del_init(&next->queuelist); +} + +static int noop_dispatch(request_queue_t *q, int force) +{ + struct noop_data *nd = q->elevator->elevator_data; + + if (!list_empty(&nd->queue)) { + struct request *rq; + rq = list_entry(nd->queue.next, struct request, queuelist); + list_del_init(&rq->queuelist); + elv_dispatch_sort(q, rq); + return 1; + } + return 0; +} + +static void noop_add_request(request_queue_t *q, struct request *rq) +{ + struct noop_data *nd = q->elevator->elevator_data; + + list_add_tail(&rq->queuelist, &nd->queue); +} + +static int noop_queue_empty(request_queue_t *q) { - rq->flags |= REQ_NOMERGE; - elv_dispatch_add_tail(q, rq); + struct noop_data *nd = q->elevator->elevator_data; + + return list_empty(&nd->queue); +} + +static struct request * +noop_former_request(request_queue_t *q, struct request *rq) +{ + struct noop_data *nd = q->elevator->elevator_data; + + if (rq->queuelist.prev == &nd->queue) + return NULL; + return list_entry(rq->queuelist.prev, struct request, queuelist); +} + +static struct request * +noop_latter_request(request_queue_t *q, struct request *rq) +{ + struct noop_data *nd = q->elevator->elevator_data; + + if (rq->queuelist.next == &nd->queue) + return NULL; + return list_entry(rq->queuelist.next, struct request, queuelist); } -static int elevator_noop_dispatch(request_queue_t *q, int force) +static int noop_init_queue(request_queue_t *q, elevator_t *e) { + struct noop_data *nd; + + nd = kmalloc(sizeof(*nd), GFP_KERNEL); + if (!nd) + return -ENOMEM; + INIT_LIST_HEAD(&nd->queue); + e->elevator_data = nd; return 0; } +static void noop_exit_queue(elevator_t *e) +{ + struct noop_data *nd = e->elevator_data; + + BUG_ON(!list_empty(&nd->queue)); + kfree(nd); +} + static struct elevator_type elevator_noop = { .ops = { - .elevator_dispatch_fn = elevator_noop_dispatch, - .elevator_add_req_fn = elevator_noop_add_request, + .elevator_merge_req_fn = noop_merged_requests, + .elevator_dispatch_fn = noop_dispatch, + .elevator_add_req_fn = noop_add_request, + .elevator_queue_empty_fn = noop_queue_empty, + .elevator_former_req_fn = noop_former_request, + .elevator_latter_req_fn = noop_latter_request, + .elevator_init_fn = noop_init_queue, + .elevator_exit_fn = noop_exit_queue, }, .elevator_name = "noop", .elevator_owner = THIS_MODULE, |
