Commit b8aca35a authored by Jens Axboe's avatar Jens Axboe Committed by Jens Axboe
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[PATCH] deadline-iosched: migrate to using the elevator rb functions 



This removes the rbtree handling from deadline.

Signed-off-by: default avatarJens Axboe <axboe@suse.de>
parent 21183b07

block/deadline-iosched.c

+34 −136
Original line number Diff line number Diff line
@@ -57,12 +57,6 @@ struct deadline_data { 
 * pre-request data.

 */

struct deadline_rq {

	/*

	 * rbtree index, key is the starting offset

	 */

	struct rb_node rb_node;

	sector_t rb_key;



	struct request *request;



	/*
@@ -78,108 +72,38 @@ static kmem_cache_t *drq_pool; 


#define RQ_DATA(rq)	((struct deadline_rq *) (rq)->elevator_private)



/*

 * rb tree support functions

 */

#define rb_entry_drq(node)	rb_entry((node), struct deadline_rq, rb_node)

#define DRQ_RB_ROOT(dd, drq)	(&(dd)->sort_list[rq_data_dir((drq)->request)])

#define rq_rb_key(rq)		(rq)->sector



static struct deadline_rq *

__deadline_add_drq_rb(struct deadline_data *dd, struct deadline_rq *drq)

{

	struct rb_node **p = &DRQ_RB_ROOT(dd, drq)->rb_node;

	struct rb_node *parent = NULL;

	struct deadline_rq *__drq;



	while (*p) {

		parent = *p;

		__drq = rb_entry_drq(parent);



		if (drq->rb_key < __drq->rb_key)

			p = &(*p)->rb_left;

		else if (drq->rb_key > __drq->rb_key)

			p = &(*p)->rb_right;

		else

			return __drq;

	}



	rb_link_node(&drq->rb_node, parent, p);

	return NULL;

}

#define RQ_RB_ROOT(dd, rq)	(&(dd)->sort_list[rq_data_dir((rq))])

#define DRQ_RB_ROOT(dd, drq)	RQ_RB_ROOT((drq)->request)



static void

deadline_add_drq_rb(struct deadline_data *dd, struct deadline_rq *drq)

deadline_add_drq_rb(struct deadline_data *dd, struct request *rq)

{

	struct deadline_rq *__alias;



	drq->rb_key = rq_rb_key(drq->request);

	struct rb_root *root = RQ_RB_ROOT(dd, rq);

	struct request *__alias;



retry:

	__alias = __deadline_add_drq_rb(dd, drq);

	if (!__alias) {

		rb_insert_color(&drq->rb_node, DRQ_RB_ROOT(dd, drq));

		return;

	}



	deadline_move_request(dd, __alias);

	__alias = elv_rb_add(root, rq);

	if (unlikely(__alias)) {

		deadline_move_request(dd, RQ_DATA(__alias));

		goto retry;

	}

}



static inline void

deadline_del_drq_rb(struct deadline_data *dd, struct deadline_rq *drq)

{

	const int data_dir = rq_data_dir(drq->request);

	struct request *rq = drq->request;

	const int data_dir = rq_data_dir(rq);



	if (dd->next_drq[data_dir] == drq) {

		struct rb_node *rbnext = rb_next(&drq->rb_node);

		struct rb_node *rbnext = rb_next(&rq->rb_node);



		dd->next_drq[data_dir] = NULL;

		if (rbnext)

			dd->next_drq[data_dir] = rb_entry_drq(rbnext);

	}



	BUG_ON(!RB_EMPTY_NODE(&drq->rb_node));

	rb_erase(&drq->rb_node, DRQ_RB_ROOT(dd, drq));

	RB_CLEAR_NODE(&drq->rb_node);

}



static struct request *

deadline_find_drq_rb(struct deadline_data *dd, sector_t sector, int data_dir)

{

	struct rb_node *n = dd->sort_list[data_dir].rb_node;

	struct deadline_rq *drq;



	while (n) {

		drq = rb_entry_drq(n);



		if (sector < drq->rb_key)

			n = n->rb_left;

		else if (sector > drq->rb_key)

			n = n->rb_right;

		else

			return drq->request;

	}



	return NULL;

			dd->next_drq[data_dir] = RQ_DATA(rb_entry_rq(rbnext));

	}



/*

 * deadline_find_first_drq finds the first (lowest sector numbered) request

 * for the specified data_dir. Used to sweep back to the start of the disk

 * (1-way elevator) after we process the last (highest sector) request.

 */

static struct deadline_rq *

deadline_find_first_drq(struct deadline_data *dd, int data_dir)

{

	struct rb_node *n = dd->sort_list[data_dir].rb_node;



	for (;;) {

		if (n->rb_left == NULL)

			return rb_entry_drq(n);

		

		n = n->rb_left;

	}

	elv_rb_del(RQ_RB_ROOT(dd, rq), rq);

}



/*
@@ -192,7 +116,7 @@ deadline_add_request(struct request_queue *q, struct request *rq) 
	struct deadline_rq *drq = RQ_DATA(rq);

	const int data_dir = rq_data_dir(drq->request);



	deadline_add_drq_rb(dd, drq);

	deadline_add_drq_rb(dd, rq);



	/*

	 * set expire time (only used for reads) and add to fifo list
@@ -224,11 +148,11 @@ deadline_merge(request_queue_t *q, struct request **req, struct bio *bio) 
	 * check for front merge

	 */

	if (dd->front_merges) {

		sector_t rb_key = bio->bi_sector + bio_sectors(bio);

		sector_t sector = bio->bi_sector + bio_sectors(bio);



		__rq = deadline_find_drq_rb(dd, rb_key, bio_data_dir(bio));

		__rq = elv_rb_find(&dd->sort_list[bio_data_dir(bio)], sector);

		if (__rq) {

			BUG_ON(rb_key != rq_rb_key(__rq));

			BUG_ON(sector != __rq->sector);



			if (elv_rq_merge_ok(__rq, bio)) {

				ret = ELEVATOR_FRONT_MERGE;
@@ -243,17 +167,17 @@ deadline_merge(request_queue_t *q, struct request **req, struct bio *bio) 
	return ret;

}



static void deadline_merged_request(request_queue_t *q, struct request *req)

static void deadline_merged_request(request_queue_t *q, struct request *req,

				    int type)

{

	struct deadline_data *dd = q->elevator->elevator_data;

	struct deadline_rq *drq = RQ_DATA(req);



	/*

	 * if the merge was a front merge, we need to reposition request

	 */

	if (rq_rb_key(req) != drq->rb_key) {

		deadline_del_drq_rb(dd, drq);

		deadline_add_drq_rb(dd, drq);

	if (type == ELEVATOR_FRONT_MERGE) {

		elv_rb_del(RQ_RB_ROOT(dd, req), req);

		deadline_add_drq_rb(dd, req);

	}

}
@@ -261,18 +185,12 @@ static void 
deadline_merged_requests(request_queue_t *q, struct request *req,

			 struct request *next)

{

	struct deadline_data *dd = q->elevator->elevator_data;

	struct deadline_rq *drq = RQ_DATA(req);

	struct deadline_rq *dnext = RQ_DATA(next);



	BUG_ON(!drq);

	BUG_ON(!dnext);



	if (rq_rb_key(req) != drq->rb_key) {

		deadline_del_drq_rb(dd, drq);

		deadline_add_drq_rb(dd, drq);

	}



	/*

	 * if dnext expires before drq, assign its expire time to drq

	 * and move into dnext position (dnext will be deleted) in fifo
@@ -308,14 +226,15 @@ deadline_move_to_dispatch(struct deadline_data *dd, struct deadline_rq *drq) 
static void

deadline_move_request(struct deadline_data *dd, struct deadline_rq *drq)

{

	const int data_dir = rq_data_dir(drq->request);

	struct rb_node *rbnext = rb_next(&drq->rb_node);

	struct request *rq = drq->request;

	const int data_dir = rq_data_dir(rq);

	struct rb_node *rbnext = rb_next(&rq->rb_node);



	dd->next_drq[READ] = NULL;

	dd->next_drq[WRITE] = NULL;



	if (rbnext)

		dd->next_drq[data_dir] = rb_entry_drq(rbnext);

		dd->next_drq[data_dir] = RQ_DATA(rb_entry_rq(rbnext));

	

	dd->last_sector = drq->request->sector + drq->request->nr_sectors;
@@ -426,13 +345,17 @@ static int deadline_dispatch_requests(request_queue_t *q, int force) 
		 */

		drq = dd->next_drq[data_dir];

	} else {

		struct rb_node *n;



		/*

		 * 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;

		drq = deadline_find_first_drq(dd, data_dir);

		n = rb_first(&dd->sort_list[data_dir]);

		if (n)

			drq = RQ_DATA(rb_entry_rq(n));

	}



dispatch_request:
@@ -453,30 +376,6 @@ static int deadline_queue_empty(request_queue_t *q) 
		&& list_empty(&dd->fifo_list[READ]);

}



static struct request *

deadline_former_request(request_queue_t *q, struct request *rq)

{

	struct deadline_rq *drq = RQ_DATA(rq);

	struct rb_node *rbprev = rb_prev(&drq->rb_node);



	if (rbprev)

		return rb_entry_drq(rbprev)->request;



	return NULL;

}



static struct request *

deadline_latter_request(request_queue_t *q, struct request *rq)

{

	struct deadline_rq *drq = RQ_DATA(rq);

	struct rb_node *rbnext = rb_next(&drq->rb_node);



	if (rbnext)

		return rb_entry_drq(rbnext)->request;



	return NULL;

}



static void deadline_exit_queue(elevator_t *e)

{

	struct deadline_data *dd = e->elevator_data;
@@ -542,7 +441,6 @@ deadline_set_request(request_queue_t *q, struct request *rq, struct bio *bio, 
	drq = mempool_alloc(dd->drq_pool, gfp_mask);

	if (drq) {

		memset(drq, 0, sizeof(*drq));

		RB_CLEAR_NODE(&drq->rb_node);

		drq->request = rq;



		INIT_LIST_HEAD(&drq->fifo);
@@ -633,8 +531,8 @@ static struct elevator_type iosched_deadline = { 
		.elevator_dispatch_fn =		deadline_dispatch_requests,

		.elevator_add_req_fn =		deadline_add_request,

		.elevator_queue_empty_fn =	deadline_queue_empty,

		.elevator_former_req_fn =	deadline_former_request,

		.elevator_latter_req_fn =	deadline_latter_request,

		.elevator_former_req_fn =	elv_rb_former_request,

		.elevator_latter_req_fn =	elv_rb_latter_request,

		.elevator_set_req_fn =		deadline_set_request,

		.elevator_put_req_fn = 		deadline_put_request,

		.elevator_init_fn =		deadline_init_queue,