Revert "block: recursive merge requests"

This reverts commit 2741932. We have some problems related to selection of empty queues that need to be resolved, evidence so far points to the recursive merge logic making either being the cause or at least the accelerator for this. So revert it for now, until we figure this out. Signed-off-by: Jens Axboe <[email protected]>
micronews · Jan 15, 2012 · 5d381ef · 5d381ef
1 parent 6898e3b
commit 5d381ef
Showing 1 changed file with 4 additions and 12 deletions.
diff --git a/block/elevator.c b/block/elevator.c
@@ -515,7 +515,6 @@ static bool elv_attempt_insert_merge(struct request_queue *q,
 				     struct request *rq)
 {
 	struct request *__rq;
-	bool ret;
 
 	if (blk_queue_nomerges(q))
 		return false;
@@ -529,21 +528,14 @@ static bool elv_attempt_insert_merge(struct request_queue *q,
 	if (blk_queue_noxmerges(q))
 		return false;
 
-	ret = false;
 	/*
 	 * See if our hash lookup can find a potential backmerge.
 	 */
-	while (1) {
-		__rq = elv_rqhash_find(q, blk_rq_pos(rq));
-		if (!__rq || !blk_attempt_req_merge(q, __rq, rq))
-			break;
-
-		/* The merged request could be merged with others, try again */
-		ret = true;
-		rq = __rq;
-	}
+	__rq = elv_rqhash_find(q, blk_rq_pos(rq));
+	if (__rq && blk_attempt_req_merge(q, __rq, rq))
+		return true;
 
-	return ret;
+	return false;
 }
 
 void elv_merged_request(struct request_queue *q, struct request *rq, int type)