From bae386f7884aa3720cc7880b36a41a1d2b9c327b Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Mon, 24 Apr 2006 21:12:59 +0200 Subject: [PATCH] iosched: use hlist for request hashtable Use hlist instead of list_head for request hashtable in deadline-iosched and as-iosched. It also can remove the flag to know hashed or unhashed. Signed-off-by: Akinobu Mita Signed-off-by: Jens Axboe block/as-iosched.c | 45 +++++++++++++++++++-------------------------- block/deadline-iosched.c | 39 ++++++++++++++++----------------------- 2 files changed, 35 insertions(+), 49 deletions(-) --- block/as-iosched.c | 45 +++++++++++++++++++-------------------------- 1 file changed, 19 insertions(+), 26 deletions(-) (limited to 'block/as-iosched.c') diff --git a/block/as-iosched.c b/block/as-iosched.c index 0c750393be4..9b13d72ffef 100644 --- a/block/as-iosched.c +++ b/block/as-iosched.c @@ -96,7 +96,7 @@ struct as_data { struct as_rq *next_arq[2]; /* next in sort order */ sector_t last_sector[2]; /* last REQ_SYNC & REQ_ASYNC sectors */ - struct list_head *hash; /* request hash */ + struct hlist_head *hash; /* request hash */ unsigned long exit_prob; /* probability a task will exit while being waited on */ @@ -165,8 +165,7 @@ struct as_rq { /* * request hash, key is the ending offset (for back merge lookup) */ - struct list_head hash; - unsigned int on_hash; + struct hlist_node hash; /* * expire fifo @@ -282,17 +281,15 @@ static const int as_hash_shift = 6; #define AS_HASH_FN(sec) (hash_long(AS_HASH_BLOCK((sec)), as_hash_shift)) #define AS_HASH_ENTRIES (1 << as_hash_shift) #define rq_hash_key(rq) ((rq)->sector + (rq)->nr_sectors) -#define list_entry_hash(ptr) list_entry((ptr), struct as_rq, hash) static inline void __as_del_arq_hash(struct as_rq *arq) { - arq->on_hash = 0; - list_del_init(&arq->hash); + hlist_del_init(&arq->hash); } static inline void as_del_arq_hash(struct as_rq *arq) { - if (arq->on_hash) + if (!hlist_unhashed(&arq->hash)) __as_del_arq_hash(arq); } @@ -300,10 +297,9 @@ static void as_add_arq_hash(struct as_data *ad, struct as_rq *arq) { struct request *rq = arq->request; - BUG_ON(arq->on_hash); + BUG_ON(!hlist_unhashed(&arq->hash)); - arq->on_hash = 1; - list_add(&arq->hash, &ad->hash[AS_HASH_FN(rq_hash_key(rq))]); + hlist_add_head(&arq->hash, &ad->hash[AS_HASH_FN(rq_hash_key(rq))]); } /* @@ -312,31 +308,29 @@ static void as_add_arq_hash(struct as_data *ad, struct as_rq *arq) static inline void as_hot_arq_hash(struct as_data *ad, struct as_rq *arq) { struct request *rq = arq->request; - struct list_head *head = &ad->hash[AS_HASH_FN(rq_hash_key(rq))]; + struct hlist_head *head = &ad->hash[AS_HASH_FN(rq_hash_key(rq))]; - if (!arq->on_hash) { + if (hlist_unhashed(&arq->hash)) { WARN_ON(1); return; } - if (arq->hash.prev != head) { - list_del(&arq->hash); - list_add(&arq->hash, head); + if (&arq->hash != head->first) { + hlist_del(&arq->hash); + hlist_add_head(&arq->hash, head); } } static struct request *as_find_arq_hash(struct as_data *ad, sector_t offset) { - struct list_head *hash_list = &ad->hash[AS_HASH_FN(offset)]; - struct list_head *entry, *next = hash_list->next; + struct hlist_head *hash_list = &ad->hash[AS_HASH_FN(offset)]; + struct hlist_node *entry, *next; + struct as_rq *arq; - while ((entry = next) != hash_list) { - struct as_rq *arq = list_entry_hash(entry); + hlist_for_each_entry_safe(arq, entry, next, hash_list, hash) { struct request *__rq = arq->request; - next = entry->next; - - BUG_ON(!arq->on_hash); + BUG_ON(hlist_unhashed(&arq->hash)); if (!rq_mergeable(__rq)) { as_del_arq_hash(arq); @@ -1601,8 +1595,7 @@ static int as_set_request(request_queue_t *q, struct request *rq, arq->request = rq; arq->state = AS_RQ_PRESCHED; arq->io_context = NULL; - INIT_LIST_HEAD(&arq->hash); - arq->on_hash = 0; + INIT_HLIST_NODE(&arq->hash); INIT_LIST_HEAD(&arq->fifo); rq->elevator_private = arq; return 0; @@ -1662,7 +1655,7 @@ static void *as_init_queue(request_queue_t *q, elevator_t *e) ad->q = q; /* Identify what queue the data belongs to */ - ad->hash = kmalloc_node(sizeof(struct list_head)*AS_HASH_ENTRIES, + ad->hash = kmalloc_node(sizeof(struct hlist_head)*AS_HASH_ENTRIES, GFP_KERNEL, q->node); if (!ad->hash) { kfree(ad); @@ -1684,7 +1677,7 @@ static void *as_init_queue(request_queue_t *q, elevator_t *e) INIT_WORK(&ad->antic_work, as_work_handler, q); for (i = 0; i < AS_HASH_ENTRIES; i++) - INIT_LIST_HEAD(&ad->hash[i]); + INIT_HLIST_HEAD(&ad->hash[i]); INIT_LIST_HEAD(&ad->fifo_list[REQ_SYNC]); INIT_LIST_HEAD(&ad->fifo_list[REQ_ASYNC]); -- cgit v1.2.3