From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Aloni Subject: [PATCH] scsi_execute_async() should add to the tail of the queue Date: Tue, 19 Dec 2006 02:02:34 +0200 Message-ID: <20061219000234.GA5330@localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from noname.neutralserver.com ([70.84.186.210]:20611 "EHLO noname.neutralserver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932761AbWLSKcy (ORCPT ); Tue, 19 Dec 2006 05:32:54 -0500 Content-Disposition: inline Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Linux Kernel List Cc: linux-scsi@vger.kernel.org, Mike Christie 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 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