--- /opt/kernel/linux-2.4.0-test7/drivers/block/ll_rw_blk.c	Thu Aug 24 05:12:54 2000
+++ drivers/block/ll_rw_blk.c	Thu Aug 24 19:42:22 2000
@@ -423,6 +423,7 @@
 	INIT_LIST_HEAD(&q->queue_head);
 	INIT_LIST_HEAD(&q->request_freelist[READ]);
 	INIT_LIST_HEAD(&q->request_freelist[WRITE]);
+	INIT_LIST_HEAD(&q->pending_freelist);
 	elevator_init(&q->elevator, ELEVATOR_LINUS);
 	blk_init_free_list(q);
 	q->request_fn     	= rfn;
@@ -442,6 +443,7 @@
 	 */
 	q->plug_device_fn 	= generic_plug_device;
 	q->head_active    	= 1;
+	q->pending_free		= 0;
 }
 
 
@@ -494,9 +496,9 @@
 	register struct request *rq;
 	DECLARE_WAITQUEUE(wait, current);
 
-	add_wait_queue_exclusive(&q->wait_for_request, &wait);
+	add_wait_queue(&q->wait_for_request, &wait);
 	for (;;) {
-		__set_current_state(TASK_UNINTERRUPTIBLE | TASK_EXCLUSIVE);
+		__set_current_state(TASK_UNINTERRUPTIBLE);
 		spin_lock_irq(&io_request_lock);
 		rq = get_request(q, rw);
 		spin_unlock_irq(&io_request_lock);
@@ -604,20 +606,52 @@
 		(q->request_fn)(q);
 }
 
+void inline blkdev_flush_pending_free(request_queue_t *q)
+{
+	struct list_head *p = &q->pending_freelist;
+	struct request *rq;
+	p = p->next;
+	do {
+		rq = list_entry(p, struct request, table);
+		p = p->next;
+		list_del(&rq->table);
+		list_add(&rq->table, rq->free_list);
+	} while (!list_empty(&q->pending_freelist));
+	q->pending_free = 0;
+}
+
 /*
  * Must be called with io_request_lock held and interrupts disabled
  */
 void inline blkdev_release_request(struct request *req)
 {
+	request_queue_t *q = req->q;
 	req->rq_status = RQ_INACTIVE;
 
 	/*
 	 * Request may not have originated from ll_rw_blk
 	 */
-	if (req->free_list) {
+	if (req->free_list == NULL)
+		return;
+
+	/*
+	 * no one waiting for free requests
+	 */
+	if (!waitqueue_active(&q->wait_for_request)) {
+		if (!list_empty(&q->pending_freelist))
+			blkdev_flush_pending_free(q);
 		list_add(&req->table, req->free_list);
 		req->free_list = NULL;
-		wake_up(&req->q->wait_for_request);
+		return;
+	}
+
+	/*
+	 * batch request freeing
+	 */
+	list_add(&req->table, &q->pending_freelist);
+	if (++q->pending_free > QUEUE_NR_REQUESTS >> 2) {
+		blkdev_flush_pending_free(q);
+		wake_up(&q->wait_for_request);
 	}
 }
 
--- /opt/kernel/linux-2.4.0-test7/include/linux/blkdev.h	Thu Aug 10 14:28:06 2000
+++ include/linux/blkdev.h	Thu Aug 24 18:44:56 2000
@@ -77,6 +77,7 @@
 	 * the queue request freelist, one for reads and one for writes
 	 */
 	struct list_head	request_freelist[2];
+	struct list_head	pending_freelist;
 
 	/*
 	 * Together with queue_head for cacheline sharing
@@ -122,6 +123,7 @@
 	 * Tasks wait here for free request
 	 */
 	wait_queue_head_t	wait_for_request;
+	int			pending_free;
 };
 
 struct blk_dev_struct {