On Tue, Feb 04, 2003 at 12:33:23PM -0600, James Bottomley wrote:
> I agree with this.  It is a guarantee the mid-layer makes to the LLD
> (and there are some LLDs with static issue queues for which this is a
> hard requirement).  I think (once the dust has settled and we've agreed
> which field holds the current queue depth) what's needed is a check in
> the scsi_request_fn() to see if we're over the LLD's current depth for
> the device and plug the queue and exit if we are.  The next returning
> command will unplug and send.
>
> This way of doing things means that we're free to prep as many commands
> as we can, but we guarantee only to have the correct number outstanding
> to the LLD.

Okay, here's a new versin of the patch.  Changes:

* throttel on number of inflight command blocks
* rename scsi_cmnd->new_queue_depth to scsi_cmnd->queue_depth
* remove scsi_do_cmd
* serialize pool handling