[PATCH] scsi_execute_async() should add to the tail of the queue

Dan Aloni
2006-12-19T08:35:39Z

Hello,

scsi_execute_async() has replaced scsi_do_req() a few versions ago,
but it also incurred a change of behavior. I noticed that over-queuing
a SCSI device using that function causes I/Os to be starved from
low-level queuing for no justified reason.

I think it makes much more sense to perserve the original behaviour
of scsi_do_req() and add the request to the tail of the queue.

Signed-off-by: Dan Aloni <da-x@monatomic.org>

diff -p -urN a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
--- a/drivers/scsi/scsi_lib.c 2006-12-19 01:48:50.000000000 +0200
+++ b/drivers/scsi/scsi_lib.c 2006-12-19 01:49:35.000000000 +0200
@@ -421,7 +421,7 @@ int scsi_execute_async(struct scsi_devic
sioc->data = privdata;
sioc->done = done;

- blk_execute_rq_nowait(req->q, NULL, req, 1, scsi_end_async);
+ blk_execute_rq_nowait(req->q, NULL, req, 0, scsi_end_async);
return 0;

free_req:

- Dan