Re: [Hdaps-devel] Re: HDAPS, Need to park the head for real

Jens Axboe
2005-08-26T06:49:43Z

On Thu, Aug 25 2005, Jon Escombe wrote:
> Alan Cox wrote:
> >@@ -1661,6 +1671,9 @@
> > where = ELEVATOR_INSERT_FRONT;
> > rq->flags |= REQ_PREEMPT;
> > }
> >+ if (action == ide_next)
> >+ where = ELEVATOR_INSERT_FRONT;
> >+
> > __elv_add_request(drive->queue, rq, where, 0);
> > ide_do_request(hwgroup, IDE_NO_IRQ);
> > spin_unlock_irqrestore(&ide_lock, flags);
> >
> >Also puzzles me- why is this needed ?
>
> I wanted the park command to get in at the head of the queue (behind the
> currently executing request).
>
> Contrary to the comments for ide_do_drive_cmd(), ide_next didn't appear
> to do anything to achieve this? At least from my initial testing before
> I made this change - it could take a second or so for the park command
> to be issued if the disk was busy....

That part seems to have been lost, apparently. The above patch is
correct.

--
Jens Axboe