[PATCH] 04/05 remove last_merge handling from ioscheds

Remove last_merge handling from all ioscheds.  This patch
removes merging capability of noop iosched.

Signed-off-by: Tejun Heo <htejun@gmail.com>

1 files changed, 2 insertions, 24 deletions

diff --git a/drivers/block/cfq-iosched.c b/drivers/block/cfq-iosched.c
index 7b14160e0798..62a19ed0443b 100644
--- a/drivers/block/cfq-iosched.c
+++ b/drivers/block/cfq-iosched.c
@@ -304,14 +304,6 @@ static inline void cfq_del_crq_hash(struct cfq_rq *crq)
         hlist_del_init(&crq->hash);
 }
 
-static void cfq_remove_merge_hints(request_queue_t *q, struct cfq_rq *crq)
-{
-        cfq_del_crq_hash(crq);
-
-        if (q->last_merge == crq->request)
-                q->last_merge = NULL;
-}
-
 static inline void cfq_add_crq_hash(struct cfq_data *cfqd, struct cfq_rq *crq)
 {
         const int hash_idx = CFQ_MHASH_FN(rq_hash_key(crq->request));
@@ -672,7 +664,7 @@ static void cfq_remove_request(struct request *rq)
 
         list_del_init(&rq->queuelist);
         cfq_del_crq_rb(crq);
-        cfq_remove_merge_hints(rq->q, crq);
+        cfq_del_crq_hash(crq);
 }
 
 static int
@@ -682,12 +674,6 @@ cfq_merge(request_queue_t *q, struct request **req, struct bio *bio)
         struct request *__rq;
         int ret;
 
-        ret = elv_try_last_merge(q, bio);
-        if (ret != ELEVATOR_NO_MERGE) {
-                __rq = q->last_merge;
-                goto out_insert;
-        }
-
         __rq = cfq_find_rq_hash(cfqd, bio->bi_sector);
         if (__rq && elv_rq_merge_ok(__rq, bio)) {
                 ret = ELEVATOR_BACK_MERGE;
@@ -702,8 +688,6 @@ cfq_merge(request_queue_t *q, struct request **req, struct bio *bio)
 
         return ELEVATOR_NO_MERGE;
 out:
-        q->last_merge = __rq;
-out_insert:
         *req = __rq;
         return ret;
 }
@@ -722,8 +706,6 @@ static void cfq_merged_request(request_queue_t *q, struct request *req)
                 cfq_update_next_crq(crq);
                 cfq_reposition_crq_rb(cfqq, crq);
         }
-
-        q->last_merge = req;
 }
 
 static void
@@ -1670,13 +1652,9 @@ static void cfq_insert_request(request_queue_t *q, struct request *rq)
 
         list_add_tail(&rq->queuelist, &cfqq->fifo);
 
-        if (rq_mergeable(rq)) {
+        if (rq_mergeable(rq))
                 cfq_add_crq_hash(cfqd, crq);
 
-                if (!cfqd->queue->last_merge)
-                        cfqd->queue->last_merge = rq;
-        }
-
         cfq_crq_enqueued(cfqd, cfqq, crq);
 }