From: Hugh Dickins What purpose does loop_make_request's blk_queue_bounce serve? None, it's just a relic from before the kmaps were added to loop's transfers, and ties up mempooled resources - in the file-backed case, with no guarantee they'll soon be freed. And what purpose does loop_set_fd's blk_queue_bounce_limit serve? None, blk_queue_make_request did that. 25-akpm/drivers/block/loop.c | 3 --- 1 files changed, 3 deletions(-) diff -puN drivers/block/loop.c~loop-07-remove-blk_queue_bounce drivers/block/loop.c --- 25/drivers/block/loop.c~loop-07-remove-blk_queue_bounce Tue Jun 10 12:54:31 2003 +++ 25-akpm/drivers/block/loop.c Tue Jun 10 12:54:31 2003 @@ -548,8 +548,6 @@ static int loop_make_request(request_que goto err; } - blk_queue_bounce(q, &old_bio); - /* * file backed, queue for loop_thread to handle */ @@ -742,7 +740,6 @@ static int loop_set_fd(struct loop_devic * device */ blk_queue_make_request(&lo->lo_queue, loop_make_request); - blk_queue_bounce_limit(&lo->lo_queue, BLK_BOUNCE_HIGH); lo->lo_queue.queuedata = lo; /* _