===== drivers/block/ll_rw_blk.c 1.47 vs edited =====
--- 1.47/drivers/block/ll_rw_blk.c	Thu Jun 26 09:20:08 2003
+++ edited/drivers/block/ll_rw_blk.c	Thu Jun 26 10:52:17 2003
@@ -592,6 +592,8 @@
 	q->full			= 0;
 	q->can_throttle		= 0;
 
+	memset(q->batch, 0, sizeof(struct queue_batch) * 2);
+
 	reset_stats(q);
 
 	/*
@@ -606,6 +608,48 @@
 	blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);
 }
 
+#define MSEC(x) ((x) * 1000 / HZ)
+#define BATCH_MAX_AGE 100
+int grab_batch_ownership(request_queue_t *q, int rw)
+{
+	struct task_struct *tsk = current;
+	unsigned long age;
+	struct queue_batch *batch = q->batch + rw;
+
+	if (batch->batch_waiter)
+		return 0;
+	if (!batch->batch_owner)
+		goto grab;
+	batch->batch_waiter = tsk;
+	while(1) {
+		age = jiffies - batch->batch_jiffies;
+		if (!batch->batch_owner || MSEC(age) > BATCH_MAX_AGE)
+			break;
+		set_current_state(TASK_RUNNING);
+		spin_unlock_irq(&io_request_lock);
+		schedule();
+		spin_lock_irq(&io_request_lock);
+	}
+	batch->batch_waiter = NULL;
+grab:
+	batch->batch_owner = tsk;
+	batch->batch_jiffies = jiffies;
+	batch->batch_remaining = q->batch_requests;
+	return 1;
+}
+
+void decrement_batch_request(request_queue_t *q, int rw)
+{
+	struct queue_batch *batch = q->batch + rw;
+	if (batch->batch_owner == current) {
+		batch->batch_remaining--;
+		if (!batch->batch_remaining || 
+		    MSEC(jiffies - batch->batch_jiffies) > BATCH_MAX_AGE) {
+			batch->batch_owner = NULL;
+		}
+	}
+}
+
 #define blkdev_free_rq(list) list_entry((list)->next, struct request, queue);
 /*
  * Get a free request. io_request_lock must be held and interrupts
@@ -625,6 +669,7 @@
 		rq->cmd = rw;
 		rq->special = NULL;
 		rq->q = q;
+		decrement_batch_request(q, rw);
 	} else
 		q->full = 1;
 	return rq;
@@ -635,7 +680,7 @@
  */
 static inline struct request *get_request(request_queue_t *q, int rw)
 {
-	if (q->full)
+	if (q->full && q->batch[rw].batch_owner != current)
 		return NULL;
 	return __get_request(q, rw);
 }
@@ -698,25 +743,28 @@
 
 static struct request *__get_request_wait(request_queue_t *q, int rw)
 {
-	register struct request *rq;
+	register struct request *rq = NULL;
 	unsigned long wait_start = jiffies;
 	unsigned long time_waited;
 	DECLARE_WAITQUEUE(wait, current);
 
 	add_wait_queue_exclusive(&q->wait_for_requests, &wait);
 
+	spin_lock_irq(&io_request_lock);
 	do {
 		set_current_state(TASK_UNINTERRUPTIBLE);
-		spin_lock_irq(&io_request_lock);
 		if (q->full || blk_oversized_queue(q)) {
-			__generic_unplug_device(q);
+			if (blk_oversized_queue(q))
+				__generic_unplug_device(q);
 			spin_unlock_irq(&io_request_lock);
 			schedule();
 			spin_lock_irq(&io_request_lock);
+			if (!grab_batch_ownership(q, rw))
+				continue;
 		}
 		rq = __get_request(q, rw);
-		spin_unlock_irq(&io_request_lock);
 	} while (rq == NULL);
+	spin_unlock_irq(&io_request_lock);
 	remove_wait_queue(&q->wait_for_requests, &wait);
 	current->state = TASK_RUNNING;
 
@@ -978,9 +1026,9 @@
 		list_add(&req->queue, &q->rq.free);
 		if (q->rq.count >= q->batch_requests && !oversized_batch) {
 			smp_mb();
-			if (waitqueue_active(&q->wait_for_requests))
+			if (waitqueue_active(&q->wait_for_requests)) {
 				wake_up(&q->wait_for_requests);
-			else
+			} else
 				clear_full_and_wake(q);
 		}
 	}
===== include/linux/blkdev.h 1.25 vs edited =====
--- 1.25/include/linux/blkdev.h	Thu Jun 26 09:20:08 2003
+++ edited/include/linux/blkdev.h	Thu Jun 26 10:50:17 2003
@@ -69,6 +69,15 @@
 	struct list_head free;
 };
 
+struct queue_batch
+{
+	struct task_struct 	*batch_owner;
+	struct task_struct 	*batch_waiter;
+	unsigned long		batch_jiffies;
+	int			batch_remaining;
+	
+};
+
 struct request_queue
 {
 	/*
@@ -141,7 +150,7 @@
 	 * threshold
 	 */
 	int			full:1;
-	
+
 	/*
 	 * Boolean that indicates you will use blk_started_sectors
 	 * and blk_finished_sectors in addition to blk_started_io
@@ -162,6 +171,9 @@
 	 * Tasks wait here for free read and write requests
 	 */
 	wait_queue_head_t	wait_for_requests;
+
+	struct queue_batch	batch[2];
+
 	unsigned long           max_wait;
 	unsigned long           min_wait;
 	unsigned long           total_wait;
@@ -278,7 +290,7 @@
 
 #define MAX_SEGMENTS 128
 #define MAX_SECTORS 255
-#define MAX_QUEUE_SECTORS (2 << (20 - 9)) /* 4 mbytes when full sized */
+#define MAX_QUEUE_SECTORS (4 << (20 - 9)) /* 4 mbytes when full sized */
 #define MAX_NR_REQUESTS 1024 /* 1024k when in 512 units, normally min is 1M in 1k units */
 
 #define PageAlignSize(size) (((size) + PAGE_SIZE -1) & PAGE_MASK)