X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=block%2Felevator.c;h=8768a367fdded922a17b1c7c47ac24ec993a1628;hb=b817f6feff4a565b08f0e699a5790b4008b8f494;hp=db3d0d8296a05c908f5dd38100593217c8c7d114;hpb=d04cdb64212eb5ae6a98026a97dda626e40e8e9a;p=~andy%2Flinux

diff --git a/block/elevator.c b/block/elevator.c
index db3d0d8296a..8768a367fdd 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -33,6 +33,7 @@
 #include <linux/init.h>
 #include <linux/compiler.h>
 #include <linux/delay.h>
+#include <linux/blktrace_api.h>
 
 #include <asm/uaccess.h>
 
@@ -144,7 +145,7 @@ static int __init elevator_setup(char *str)
 		strcpy(chosen_elevator, "anticipatory");
 	else
 		strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1);
-	return 0;
+	return 1;
 }
 
 __setup("elevator=", elevator_setup);
@@ -332,6 +333,9 @@ void elv_insert(request_queue_t *q, struct request *rq, int where)
 {
 	struct list_head *pos;
 	unsigned ordseq;
+	int unplug_it = 1;
+
+	blk_add_trace_rq(q, rq, BLK_TA_INSERT);
 
 	rq->q = q;
 
@@ -396,6 +400,11 @@ void elv_insert(request_queue_t *q, struct request *rq, int where)
 		}
 
 		list_add_tail(&rq->queuelist, pos);
+		/*
+		 * most requeues happen because of a busy condition, don't
+		 * force unplug of the queue for that case.
+		 */
+		unplug_it = 0;
 		break;
 
 	default:
@@ -404,7 +413,7 @@ void elv_insert(request_queue_t *q, struct request *rq, int where)
 		BUG();
 	}
 
-	if (blk_queue_plugged(q)) {
+	if (unplug_it && blk_queue_plugged(q)) {
 		int nrq = q->rq.count[READ] + q->rq.count[WRITE]
 			- q->in_flight;
 
@@ -499,6 +508,7 @@ struct request *elv_next_request(request_queue_t *q)
 			 * not be passed by new incoming requests
 			 */
 			rq->flags |= REQ_STARTED;
+			blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
 		}
 
 		if (!q->boundary_rq || q->boundary_rq == rq) {
@@ -724,8 +734,7 @@ void elv_unregister_queue(struct request_queue *q)
 int elv_register(struct elevator_type *e)
 {
 	spin_lock_irq(&elv_list_lock);
-	if (elevator_find(e->elevator_name))
-		BUG();
+	BUG_ON(elevator_find(e->elevator_name));
 	list_add_tail(&e->list, &elv_list);
 	spin_unlock_irq(&elv_list_lock);
 
@@ -892,10 +901,8 @@ ssize_t elv_iosched_show(request_queue_t *q, char *name)
 EXPORT_SYMBOL(elv_dispatch_sort);
 EXPORT_SYMBOL(elv_add_request);
 EXPORT_SYMBOL(__elv_add_request);
-EXPORT_SYMBOL(elv_requeue_request);
 EXPORT_SYMBOL(elv_next_request);
 EXPORT_SYMBOL(elv_dequeue_request);
 EXPORT_SYMBOL(elv_queue_empty);
-EXPORT_SYMBOL(elv_completed_request);
 EXPORT_SYMBOL(elevator_exit);
 EXPORT_SYMBOL(elevator_init);