diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/cfq-iosched.c | 164 |
1 files changed, 41 insertions, 123 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 1b803c0..b2fd8ca 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -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); - - return cfq_choose_req(cfqd, crq_next, crq_prev); -} + prev = RQ_DATA(rb_entry_rq(rbprev)); -static void cfq_update_next_crq(struct cfq_rq *crq) -{ - struct cfq_queue *cfqq = crq->cfq_queue; + 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)); + } - 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); @@ -1700,6 +1635,12 @@ 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, |
