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-rw-r--r--block/as-iosched.c139
1 files changed, 3 insertions, 136 deletions
diff --git a/block/as-iosched.c b/block/as-iosched.c
index ad1cc4077819b6..6db494333c3a55 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -14,7 +14,6 @@
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/compiler.h>
-#include <linux/hash.h>
#include <linux/rbtree.h>
#include <linux/interrupt.h>
@@ -95,7 +94,6 @@ 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 hlist_head *hash; /* request hash */
unsigned long exit_prob; /* probability a task will exit while
being waited on */
@@ -162,11 +160,6 @@ struct as_rq {
struct io_context *io_context; /* The submitting task */
/*
- * request hash, key is the ending offset (for back merge lookup)
- */
- struct hlist_node hash;
-
- /*
* expire fifo
*/
struct list_head fifo;
@@ -273,77 +266,6 @@ static void as_put_io_context(struct as_rq *arq)
}
/*
- * the back merge hash support functions
- */
-static const int as_hash_shift = 6;
-#define AS_HASH_BLOCK(sec) ((sec) >> 3)
-#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)
-
-static inline void __as_del_arq_hash(struct as_rq *arq)
-{
- hlist_del_init(&arq->hash);
-}
-
-static inline void as_del_arq_hash(struct as_rq *arq)
-{
- if (!hlist_unhashed(&arq->hash))
- __as_del_arq_hash(arq);
-}
-
-static void as_add_arq_hash(struct as_data *ad, struct as_rq *arq)
-{
- struct request *rq = arq->request;
-
- BUG_ON(!hlist_unhashed(&arq->hash));
-
- hlist_add_head(&arq->hash, &ad->hash[AS_HASH_FN(rq_hash_key(rq))]);
-}
-
-/*
- * move hot entry to front of chain
- */
-static inline void as_hot_arq_hash(struct as_data *ad, struct as_rq *arq)
-{
- struct request *rq = arq->request;
- struct hlist_head *head = &ad->hash[AS_HASH_FN(rq_hash_key(rq))];
-
- if (hlist_unhashed(&arq->hash)) {
- WARN_ON(1);
- return;
- }
-
- 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 hlist_head *hash_list = &ad->hash[AS_HASH_FN(offset)];
- struct hlist_node *entry, *next;
- struct as_rq *arq;
-
- hlist_for_each_entry_safe(arq, entry, next, hash_list, hash) {
- struct request *__rq = arq->request;
-
- BUG_ON(hlist_unhashed(&arq->hash));
-
- if (!rq_mergeable(__rq)) {
- as_del_arq_hash(arq);
- continue;
- }
-
- if (rq_hash_key(__rq) == offset)
- return __rq;
- }
-
- return NULL;
-}
-
-/*
* rb tree support functions
*/
#define rb_entry_arq(node) rb_entry((node), struct as_rq, rb_node)
@@ -1060,7 +982,6 @@ static void as_remove_queued_request(request_queue_t *q, struct request *rq)
ad->next_arq[data_dir] = as_find_next_arq(ad, arq);
list_del_init(&arq->fifo);
- as_del_arq_hash(arq);
as_del_arq_rb(ad, arq);
}
@@ -1349,8 +1270,6 @@ static void as_add_request(request_queue_t *q, struct request *rq)
}
as_add_arq_rb(ad, arq);
- if (rq_mergeable(arq->request))
- as_add_arq_hash(ad, arq);
/*
* set expire time (only used for reads) and add to fifo list
@@ -1428,42 +1347,17 @@ as_merge(request_queue_t *q, struct request **req, struct bio *bio)
struct as_data *ad = q->elevator->elevator_data;
sector_t rb_key = bio->bi_sector + bio_sectors(bio);
struct request *__rq;
- int ret;
-
- /*
- * see if the merge hash can satisfy a back merge
- */
- __rq = as_find_arq_hash(ad, bio->bi_sector);
- if (__rq) {
- BUG_ON(__rq->sector + __rq->nr_sectors != bio->bi_sector);
-
- if (elv_rq_merge_ok(__rq, bio)) {
- ret = ELEVATOR_BACK_MERGE;
- goto out;
- }
- }
/*
* check for front merge
*/
__rq = as_find_arq_rb(ad, rb_key, bio_data_dir(bio));
- if (__rq) {
- BUG_ON(rb_key != rq_rb_key(__rq));
-
- if (elv_rq_merge_ok(__rq, bio)) {
- ret = ELEVATOR_FRONT_MERGE;
- goto out;
- }
+ if (__rq && elv_rq_merge_ok(__rq, bio)) {
+ *req = __rq;
+ return ELEVATOR_FRONT_MERGE;
}
return ELEVATOR_NO_MERGE;
-out:
- if (ret) {
- if (rq_mergeable(__rq))
- as_hot_arq_hash(ad, RQ_DATA(__rq));
- }
- *req = __rq;
- return ret;
}
static void as_merged_request(request_queue_t *q, struct request *req)
@@ -1472,12 +1366,6 @@ static void as_merged_request(request_queue_t *q, struct request *req)
struct as_rq *arq = RQ_DATA(req);
/*
- * hash always needs to be repositioned, key is end sector
- */
- as_del_arq_hash(arq);
- as_add_arq_hash(ad, arq);
-
- /*
* if the merge was a front merge, we need to reposition request
*/
if (rq_rb_key(req) != arq->rb_key) {
@@ -1501,13 +1389,6 @@ static void as_merged_requests(request_queue_t *q, struct request *req,
BUG_ON(!arq);
BUG_ON(!anext);
- /*
- * reposition arq (this is the merged request) in hash, and in rbtree
- * in case of a front merge
- */
- as_del_arq_hash(arq);
- as_add_arq_hash(ad, arq);
-
if (rq_rb_key(req) != arq->rb_key) {
as_del_arq_rb(ad, arq);
as_add_arq_rb(ad, arq);
@@ -1591,7 +1472,6 @@ 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_HLIST_NODE(&arq->hash);
INIT_LIST_HEAD(&arq->fifo);
rq->elevator_private = arq;
return 0;
@@ -1628,7 +1508,6 @@ static void as_exit_queue(elevator_t *e)
mempool_destroy(ad->arq_pool);
put_io_context(ad->io_context);
- kfree(ad->hash);
kfree(ad);
}
@@ -1639,7 +1518,6 @@ static void as_exit_queue(elevator_t *e)
static void *as_init_queue(request_queue_t *q, elevator_t *e)
{
struct as_data *ad;
- int i;
if (!arq_pool)
return NULL;
@@ -1651,17 +1529,9 @@ 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 hlist_head)*AS_HASH_ENTRIES,
- GFP_KERNEL, q->node);
- if (!ad->hash) {
- kfree(ad);
- return NULL;
- }
-
ad->arq_pool = mempool_create_node(BLKDEV_MIN_RQ, mempool_alloc_slab,
mempool_free_slab, arq_pool, q->node);
if (!ad->arq_pool) {
- kfree(ad->hash);
kfree(ad);
return NULL;
}
@@ -1672,9 +1542,6 @@ static void *as_init_queue(request_queue_t *q, elevator_t *e)
init_timer(&ad->antic_timer);
INIT_WORK(&ad->antic_work, as_work_handler, q);
- for (i = 0; i < AS_HASH_ENTRIES; i++)
- INIT_HLIST_HEAD(&ad->hash[i]);
-
INIT_LIST_HEAD(&ad->fifo_list[REQ_SYNC]);
INIT_LIST_HEAD(&ad->fifo_list[REQ_ASYNC]);
ad->sort_list[REQ_SYNC] = RB_ROOT;
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-05-18 03:38:45 +0000