Messages in this thread |  | | Date | Mon, 30 Oct 2000 12:19:21 -0500 | From | Jeff Garzik <> | Subject | Re: [PATCH] kiobuf/rawio fixes for 2.4.0-test10-pre6 |
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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
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