GIT cca5d8ad1f58f188500b9fb12ba6d98643a4cf49 git+ssh://master.kernel.org/pub/scm/linux/kernel/git/axboe/linux-2.6-block.git#for-linus commit cca5d8ad1f58f188500b9fb12ba6d98643a4cf49 Author: Akinobu Mita Date: Mon Apr 24 21:12:59 2006 +0200 [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(-) --- diff --git a/block/as-iosched.c b/block/as-iosched.c index e25a5d7..7880cc1 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_da { 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_da 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); @@ -1602,8 +1596,7 @@ static int as_set_request(request_queue_ 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; @@ -1663,7 +1656,7 @@ static int as_init_queue(request_queue_t 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); @@ -1685,7 +1678,7 @@ static int as_init_queue(request_queue_t 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]); diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c index 399fa1e..5cdc26a 100644 --- a/block/deadline-iosched.c +++ b/block/deadline-iosched.c @@ -30,8 +30,7 @@ static const int deadline_hash_shift = 5 #define DL_HASH_FN(sec) (hash_long(DL_HASH_BLOCK((sec)), deadline_hash_shift)) #define DL_HASH_ENTRIES (1 << deadline_hash_shift) #define rq_hash_key(rq) ((rq)->sector + (rq)->nr_sectors) -#define list_entry_hash(ptr) list_entry((ptr), struct deadline_rq, hash) -#define ON_HASH(drq) (drq)->on_hash +#define ON_HASH(drq) (!hlist_unhashed(&(drq)->hash)) struct deadline_data { /* @@ -48,7 +47,7 @@ struct deadline_data { * next in sort order. read, write or both are NULL */ struct deadline_rq *next_drq[2]; - struct list_head *hash; /* request hash */ + struct hlist_head *hash; /* request hash */ unsigned int batching; /* number of sequential requests made */ sector_t last_sector; /* head position */ unsigned int starved; /* times reads have starved writes */ @@ -79,8 +78,7 @@ struct deadline_rq { /* * request hash, key is the ending offset (for back merge lookup) */ - struct list_head hash; - char on_hash; + struct hlist_node hash; /* * expire fifo @@ -100,8 +98,7 @@ static kmem_cache_t *drq_pool; */ static inline void __deadline_del_drq_hash(struct deadline_rq *drq) { - drq->on_hash = 0; - list_del_init(&drq->hash); + hlist_del_init(&drq->hash); } static inline void deadline_del_drq_hash(struct deadline_rq *drq) @@ -117,8 +114,7 @@ deadline_add_drq_hash(struct deadline_da BUG_ON(ON_HASH(drq)); - drq->on_hash = 1; - list_add(&drq->hash, &dd->hash[DL_HASH_FN(rq_hash_key(rq))]); + hlist_add_head(&drq->hash, &dd->hash[DL_HASH_FN(rq_hash_key(rq))]); } /* @@ -128,26 +124,24 @@ static inline void deadline_hot_drq_hash(struct deadline_data *dd, struct deadline_rq *drq) { struct request *rq = drq->request; - struct list_head *head = &dd->hash[DL_HASH_FN(rq_hash_key(rq))]; + struct hlist_head *head = &dd->hash[DL_HASH_FN(rq_hash_key(rq))]; - if (ON_HASH(drq) && drq->hash.prev != head) { - list_del(&drq->hash); - list_add(&drq->hash, head); + if (ON_HASH(drq) && &drq->hash != head->first) { + hlist_del(&drq->hash); + hlist_add_head(&drq->hash, head); } } static struct request * deadline_find_drq_hash(struct deadline_data *dd, sector_t offset) { - struct list_head *hash_list = &dd->hash[DL_HASH_FN(offset)]; - struct list_head *entry, *next = hash_list->next; + struct hlist_head *hash_list = &dd->hash[DL_HASH_FN(offset)]; + struct hlist_node *entry, *next; + struct deadline_rq *drq; - while ((entry = next) != hash_list) { - struct deadline_rq *drq = list_entry_hash(entry); + hlist_for_each_entry_safe(drq, entry, next, hash_list, hash) { struct request *__rq = drq->request; - next = entry->next; - BUG_ON(!ON_HASH(drq)); if (!rq_mergeable(__rq)) { @@ -626,7 +620,7 @@ static int deadline_init_queue(request_q return -ENOMEM; memset(dd, 0, sizeof(*dd)); - dd->hash = kmalloc_node(sizeof(struct list_head)*DL_HASH_ENTRIES, + dd->hash = kmalloc_node(sizeof(struct hlist_head)*DL_HASH_ENTRIES, GFP_KERNEL, q->node); if (!dd->hash) { kfree(dd); @@ -642,7 +636,7 @@ static int deadline_init_queue(request_q } for (i = 0; i < DL_HASH_ENTRIES; i++) - INIT_LIST_HEAD(&dd->hash[i]); + INIT_HLIST_HEAD(&dd->hash[i]); INIT_LIST_HEAD(&dd->fifo_list[READ]); INIT_LIST_HEAD(&dd->fifo_list[WRITE]); @@ -679,8 +673,7 @@ deadline_set_request(request_queue_t *q, RB_CLEAR(&drq->rb_node); drq->request = rq; - INIT_LIST_HEAD(&drq->hash); - drq->on_hash = 0; + INIT_HLIST_NODE(&drq->hash); INIT_LIST_HEAD(&drq->fifo);