Messages in this thread | | | Date | Wed, 20 Dec 2006 20:40:29 +0000 | From | Steven Hayter <> | Subject | Re: [PATCH] scsi_execute_async() should add to the tail of the queue |
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Dan Aloni wrote: > 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.
As far as I'm aware the way in which scsi_do_req() was to insert at the head of the queue, leading to projects like SCST to come up with scsi_do_req_fifo() as queuing multiple commands using scsi_do_req() with constant head insertion might lead to out of order execution.
Just thought I'd throw some light on the history and what others have done in the past.
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