Re: [PATCH] iSeries virtual disk

[Jens Axboe]

On Thu, Feb 26 2004, Jeff Garzik wrote:
> 4) why do you call blkdev_dequeue_request() in do_viodasd_request() 
> rather than viodasd_end_request() ?  Or just use end_request() ?

It makes the queueing simpler (you could potentially leave the _last_
request on the queue, but it's probably not worth the hassle).

They should not call elv_next_request() only to bail if
num_req_outstanding is too big, since it has side effects (moving
request from io scheduler core to dispatch, which makes it ineligible
for merging, sorting, etc).

	do {
		if (too_many_queued)
			break;

		rq = elv_next_request(q);
		if (!rq)
			break;

		...
	}

> 12) don't you need to set blk_queue_max_phys_segments() too?

Yep

> P.S.  I so wish that people had named the API function 
> dma_alloc_incoherent() rather than dma_alloc_noncoherent :)

;-)

-- 
Jens Axboe

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