[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 <mita@miraclelinux.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
block/as-iosched.c | 45 +++++++++++++++++++--------------------------
block/deadline-iosched.c | 39 ++++++++++++++++-----------------------
2 files changed, 35 insertions(+), 49 deletions(-)
diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c
index c94de8e..e5bccaa 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -30,8 +30,7 @@
#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 @@
* 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 @@
/*
* 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 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 @@
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 @@
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)) {
@@ -625,7 +619,7 @@
return NULL;
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);
@@ -641,7 +635,7 @@
}
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]);
@@ -677,8 +671,7 @@
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);