--- /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 23:49:25 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);
@@ -609,16 +611,46 @@
  */
 void inline blkdev_release_request(struct request *req)
 {
+	request_queue_t *q = req->q;
+	struct list_head *write_list = &q->request_freelist[WRITE];
+
 	req->rq_status = RQ_INACTIVE;
 
 	/*
 	 * Request may not have originated from ll_rw_blk
 	 */
-	if (req->free_list) {
-		list_add(&req->table, req->free_list);
-		req->free_list = NULL;
-		wake_up(&req->q->wait_for_request);
+	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)) {
+			list_splice(&q->pending_freelist, write_list);
+			INIT_LIST_HEAD(&q->pending_freelist);
+		}
+		goto add;
 	}
+
+	if (req->free_list == &q->request_freelist[READ])
+		goto add;
+
+	/*
+	 * batch request freeing
+	 */
+	list_add(&req->table, &q->pending_freelist);
+	if (++q->pending_free > (QUEUE_NR_REQUESTS >> 2)) {
+		list_splice(&q->pending_freelist, write_list);
+		INIT_LIST_HEAD(&q->pending_freelist);
+		q->pending_free = 0;
+		wake_up(&q->wait_for_request);
+	}
+	return;
+
+add:
+	list_add(&req->table, req->free_list);
+	req->free_list = NULL;
 }
 
 /*
--- /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 23:24:59 2000
@@ -77,7 +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 +122,11 @@
 	 * Tasks wait here for free request
 	 */
 	wait_queue_head_t	wait_for_request;
+
+	/*
+	 * for batch-freeing of released requests
+	 */
+	int			pending_free;
 };
 
 struct blk_dev_struct {