Commit 21183b07 authored by Jens Axboe's avatar Jens Axboe Committed by Jens Axboe
Browse files

[PATCH] cfq-iosched: migrate to using the elevator rb functions 



This removes the rbtree handling from CFQ.

Signed-off-by: default avatarJens Axboe <axboe@suse.de>
parent e37f346e

block/cfq-iosched.c

+41 −123
Original line number Diff line number Diff line
@@ -46,12 +46,6 @@ static DEFINE_SPINLOCK(cfq_exit_lock); 


#define RQ_DATA(rq)		(rq)->elevator_private



/*

 * rb-tree defines

 */

#define rb_entry_crq(node)	rb_entry((node), struct cfq_rq, rb_node)

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



static kmem_cache_t *crq_pool;

static kmem_cache_t *cfq_pool;

static kmem_cache_t *cfq_ioc_pool;
@@ -185,8 +179,6 @@ struct cfq_queue { 
};



struct cfq_rq {

	struct rb_node rb_node;

	sector_t rb_key;

	struct request *request;



	struct cfq_queue *cfq_queue;
@@ -376,33 +368,27 @@ cfq_choose_req(struct cfq_data *cfqd, struct cfq_rq *crq1, struct cfq_rq *crq2) 
 */

static struct cfq_rq *

cfq_find_next_crq(struct cfq_data *cfqd, struct cfq_queue *cfqq,

		  struct cfq_rq *last)

		  struct cfq_rq *last_crq)

{

	struct cfq_rq *crq_next = NULL, *crq_prev = NULL;

	struct rb_node *rbnext, *rbprev;



	if (!(rbnext = rb_next(&last->rb_node))) {

		rbnext = rb_first(&cfqq->sort_list);

		if (rbnext == &last->rb_node)

			rbnext = NULL;

	}

	struct request *last = last_crq->request;

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

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

	struct cfq_rq *next = NULL, *prev = NULL;



	rbprev = rb_prev(&last->rb_node);

	BUG_ON(RB_EMPTY_NODE(&last->rb_node));



	if (rbprev)

		crq_prev = rb_entry_crq(rbprev);

	if (rbnext)

		crq_next = rb_entry_crq(rbnext);

		prev = RQ_DATA(rb_entry_rq(rbprev));



	return cfq_choose_req(cfqd, crq_next, crq_prev);

	if (rbnext)

		next = RQ_DATA(rb_entry_rq(rbnext));

	else {

		rbnext = rb_first(&cfqq->sort_list);

		if (rbnext && rbnext != &last->rb_node)

			next = RQ_DATA(rb_entry_rq(rbnext));

	}



static void cfq_update_next_crq(struct cfq_rq *crq)

{

	struct cfq_queue *cfqq = crq->cfq_queue;



	if (cfqq->next_crq == crq)

		cfqq->next_crq = cfq_find_next_crq(cfqq->cfqd, cfqq, crq);

	return cfq_choose_req(cfqd, next, prev);

}



static void cfq_resort_rr_list(struct cfq_queue *cfqq, int preempted)
@@ -497,71 +483,34 @@ static inline void cfq_del_crq_rb(struct cfq_rq *crq) 
	BUG_ON(!cfqq->queued[sync]);

	cfqq->queued[sync]--;



	cfq_update_next_crq(crq);



	rb_erase(&crq->rb_node, &cfqq->sort_list);

	elv_rb_del(&cfqq->sort_list, crq->request);



	if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list))

		cfq_del_cfqq_rr(cfqd, cfqq);

}



static struct cfq_rq *

__cfq_add_crq_rb(struct cfq_rq *crq)

{

	struct rb_node **p = &crq->cfq_queue->sort_list.rb_node;

	struct rb_node *parent = NULL;

	struct cfq_rq *__crq;



	while (*p) {

		parent = *p;

		__crq = rb_entry_crq(parent);



		if (crq->rb_key < __crq->rb_key)

			p = &(*p)->rb_left;

		else if (crq->rb_key > __crq->rb_key)

			p = &(*p)->rb_right;

		else

			return __crq;

	}



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

	return NULL;

}



static void cfq_add_crq_rb(struct cfq_rq *crq)

{

	struct cfq_queue *cfqq = crq->cfq_queue;

	struct cfq_data *cfqd = cfqq->cfqd;

	struct request *rq = crq->request;

	struct cfq_rq *__alias;

	struct request *__alias;



	crq->rb_key = rq_rb_key(rq);

	cfqq->queued[cfq_crq_is_sync(crq)]++;



	/*

	 * looks a little odd, but the first insert might return an alias.

	 * if that happens, put the alias on the dispatch list

	 */

	while ((__alias = __cfq_add_crq_rb(crq)) != NULL)

		cfq_dispatch_insert(cfqd->queue, __alias);



	rb_insert_color(&crq->rb_node, &cfqq->sort_list);



	if (!cfq_cfqq_on_rr(cfqq))

		cfq_add_cfqq_rr(cfqd, cfqq);



	/*

	 * check if this request is a better next-serve candidate

	 */

	cfqq->next_crq = cfq_choose_req(cfqd, cfqq->next_crq, crq);

	while ((__alias = elv_rb_add(&cfqq->sort_list, rq)) != NULL)

		cfq_dispatch_insert(cfqd->queue, RQ_DATA(__alias));

}



static inline void

cfq_reposition_crq_rb(struct cfq_queue *cfqq, struct cfq_rq *crq)

{

	rb_erase(&crq->rb_node, &cfqq->sort_list);

	elv_rb_del(&cfqq->sort_list, crq->request);

	cfqq->queued[cfq_crq_is_sync(crq)]--;



	cfq_add_crq_rb(crq);

}
@@ -570,28 +519,13 @@ cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) 
{

	struct task_struct *tsk = current;

	pid_t key = cfq_queue_pid(tsk, bio_data_dir(bio));

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

	struct cfq_queue *cfqq;

	struct rb_node *n;

	sector_t sector;



	cfqq = cfq_find_cfq_hash(cfqd, key, tsk->ioprio);

	if (!cfqq)

		goto out;



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

	n = cfqq->sort_list.rb_node;

	while (n) {

		struct cfq_rq *crq = rb_entry_crq(n);



		if (sector < crq->rb_key)

			n = n->rb_left;

		else if (sector > crq->rb_key)

			n = n->rb_right;

		else

			return crq->request;

	}

	if (cfqq)

		return elv_rb_find(&cfqq->sort_list, sector);



out:

	return NULL;

}
@@ -622,6 +556,10 @@ static void cfq_deactivate_request(request_queue_t *q, struct request *rq) 
static void cfq_remove_request(struct request *rq)

{

	struct cfq_rq *crq = RQ_DATA(rq);

	struct cfq_queue *cfqq = crq->cfq_queue;



	if (cfqq->next_crq == crq)

		cfqq->next_crq = cfq_find_next_crq(cfqq->cfqd, cfqq, crq);



	list_del_init(&rq->queuelist);

	cfq_del_crq_rb(crq);
@@ -642,14 +580,14 @@ cfq_merge(request_queue_t *q, struct request **req, struct bio *bio) 
	return ELEVATOR_NO_MERGE;

}



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

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

			       int type)

{

	struct cfq_rq *crq = RQ_DATA(req);



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

	if (type == ELEVATOR_FRONT_MERGE) {

		struct cfq_queue *cfqq = crq->cfq_queue;



		cfq_update_next_crq(crq);

		cfq_reposition_crq_rb(cfqq, crq);

	}

}
@@ -658,8 +596,6 @@ static void 
cfq_merged_requests(request_queue_t *q, struct request *rq,

		    struct request *next)

{

	cfq_merged_request(q, rq);



	/*

	 * reposition in fifo if next is older than rq

	 */
@@ -881,7 +817,6 @@ static void cfq_dispatch_insert(request_queue_t *q, struct cfq_rq *crq) 
	struct cfq_queue *cfqq = crq->cfq_queue;

	struct request *rq;



	cfqq->next_crq = cfq_find_next_crq(cfqd, cfqq, crq);

	cfq_remove_request(crq->request);

	cfqq->on_dispatch[cfq_crq_is_sync(crq)]++;

	elv_dispatch_sort(q, crq->request);
@@ -1699,6 +1634,12 @@ cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, 
{

	struct cfq_io_context *cic = crq->io_context;



	/*

	 * check if this request is a better next-serve candidate

	 */

	cfqq->next_crq = cfq_choose_req(cfqd, cfqq->next_crq, crq);

	BUG_ON(!cfqq->next_crq);



	/*

	 * we never wait for an async request and we don't allow preemption

	 * of an async request. so just return early
@@ -1756,6 +1697,9 @@ static void cfq_insert_request(request_queue_t *q, struct request *rq) 


	cfq_add_crq_rb(crq);



	if (!cfq_cfqq_on_rr(cfqq))

		cfq_add_cfqq_rr(cfqd, cfqq);



	list_add_tail(&rq->queuelist, &cfqq->fifo);



	cfq_crq_enqueued(cfqd, cfqq, crq);
@@ -1803,30 +1747,6 @@ static void cfq_completed_request(request_queue_t *q, struct request *rq) 
	}

}



static struct request *

cfq_former_request(request_queue_t *q, struct request *rq)

{

	struct cfq_rq *crq = RQ_DATA(rq);

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



	if (rbprev)

		return rb_entry_crq(rbprev)->request;



	return NULL;

}



static struct request *

cfq_latter_request(request_queue_t *q, struct request *rq)

{

	struct cfq_rq *crq = RQ_DATA(rq);

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



	if (rbnext)

		return rb_entry_crq(rbnext)->request;



	return NULL;

}



/*

 * we temporarily boost lower priority queues if they are holding fs exclusive

 * resources. they are boosted to normal prio (CLASS_BE/4)
@@ -1982,8 +1902,6 @@ cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio, 


	crq = mempool_alloc(cfqd->crq_pool, gfp_mask);

	if (crq) {

		RB_CLEAR_NODE(&crq->rb_node);

		crq->rb_key = 0;

		crq->request = rq;

		crq->cfq_queue = cfqq;

		crq->io_context = cic;
@@ -2345,8 +2263,8 @@ static struct elevator_type iosched_cfq = { 
		.elevator_deactivate_req_fn =	cfq_deactivate_request,

		.elevator_queue_empty_fn =	cfq_queue_empty,

		.elevator_completed_req_fn =	cfq_completed_request,

		.elevator_former_req_fn =	cfq_former_request,

		.elevator_latter_req_fn =	cfq_latter_request,

		.elevator_former_req_fn =	elv_rb_former_request,

		.elevator_latter_req_fn =	elv_rb_latter_request,

		.elevator_set_req_fn =		cfq_set_request,

		.elevator_put_req_fn =		cfq_put_request,

		.elevator_may_queue_fn =	cfq_may_queue,

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