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

This removes the rbtree handling from CFQ.

Signed-off-by: Jens Axboe <axboe@suse.de>
This commit is contained in:
Jens Axboe 2006-07-13 12:33:14 +02:00 committed by Jens Axboe
parent e37f346e34
commit 21183b07ee
1 changed files with 41 additions and 123 deletions
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164
block/cfq-iosched.c
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@ -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;
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;
if (!(rbnext = rb_next(&last->rb_node))) {
rbnext = rb_first(&cfqq->sort_list);
if (rbnext == &last->rb_node)
rbnext = NULL;
}
rbprev = rb_prev(&last->rb_node);
BUG_ON(RB_EMPTY_NODE(&last->rb_node));
if (rbprev)
crq_prev = rb_entry_crq(rbprev);
prev = RQ_DATA(rb_entry_rq(rbprev));
if (rbnext)
crq_next = rb_entry_crq(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));
}
return cfq_choose_req(cfqd, crq_next, crq_prev);
}
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;
if (cfqq)
return elv_rb_find(&cfqq->sort_list, sector);
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;
}
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,