Subject: [PATCH 12/20] nbd: limit blk_queue

From: Peter Zijlstra <[email-masked]>
Date: Tue, 12 Sep 2006 17:25:49 +0200

Limit each request to 1 page, so that the request throttling also limits the
number of in-flight pages.

Signed-off-by: Peter Zijlstra <[email-masked]>
Signed-off-by: Daniel Phillips <[email-masked]>
CC: Pavel Machek <[email-masked]>
---
 drivers/block/nbd.c |   17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

Index: linux-2.6/drivers/block/nbd.c
===================================================================
--- linux-2.6.orig/drivers/block/nbd.c	2006-09-07 18:43:41.000000000 +0200
+++ linux-2.6/drivers/block/nbd.c	2006-09-07 18:44:12.000000000 +0200
@@ -638,6 +638,9 @@ static int __init nbd_init(void)
 			put_disk(disk);
 			goto out;
 		}
+		blk_queue_max_segment_size(disk->queue, PAGE_SIZE);
+		blk_queue_max_hw_segments(disk->queue, 1);
+		blk_queue_max_phys_segments(disk->queue, 1);
 	}
 
 	if (register_blkdev(NBD_MAJOR, "nbd")) {

--