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From: Dan Aloni <da-x@monatomic.org>
To: Linux Kernel List <linux-kernel@vger.kernel.org>
Cc: linux-scsi@vger.kernel.org, Mike Christie <michaelc@cs.wisc.edu>
Subject: [PATCH] scsi_execute_async() should add to the tail of the queue
Date: Tue, 19 Dec 2006 02:02:34 +0200	[thread overview]
Message-ID: <20061219000234.GA5330@localdomain> (raw)

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 Aloni
XIV, http://www.xivstorage.com

             reply	other threads:[~2006-12-19 10:32 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-12-19  0:02 Dan Aloni [this message]
2006-12-20 20:40 ` [PATCH] scsi_execute_async() should add to the tail of the queue Steven Hayter
2006-12-21  7:12   ` Dan Aloni
  -- strict thread matches above, loose matches on Subject: below --
2006-12-19  8:35 Dan Aloni
2006-12-19 10:03 ` Arjan van de Ven
2006-12-19 10:34   ` Dan Aloni
2006-12-20 23:50     ` Jeremy Linton
2006-12-19 11:26   ` Jens Axboe
2006-12-19 18:34     ` Jon Escombe
2006-12-19 18:44       ` Jens Axboe

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