Re: [PATCH] kiobuf/rawio fixes for 2.4.0-test10-pre6

[Jeff Garzik <jgarzik@mandrakesoft.com>]

Christoph Hellwig wrote:
> +Locking down user memory and doing mass storage device IO with it is not
> +the only purpose of kiobufs.  Another use for kiobufs is allowing
> +user-space mmaping dma memory, e.g in sound drivers.  To do so you
> +need to lock-down kernel virtual memory and refernece it using kiobufs.
> +The code that does exactly this is not yet in the kernel - get Stephen
> +Tweedie's kiobuf patchset if you want to use this.

Take a look at drivers/sound/via82cxxx_audio.c.  How can that mmap be
improved by using kiobufs?

It seems like there is less overhead to mmap(2) DMA memory the way I do
it currently -- without kiobufs...

Honestly interested,

	Jeff


-- 
Jeff Garzik             | "Mind if I drive?"  -Sam
Building 1024           | "Not if you don't mind me clawing at the
MandrakeSoft            |  dash and shrieking like a cheerleader."
                        |                     -Max
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