Re: Kernel virtual memory?

Rogier Wolff (R.E.Wolff@BitWizard.nl)
Fri, 8 Aug 1997 17:40:48 +0200 (MET DST)

Benjamin C R LaHaise wrote:
> shuffling pages around in memory. Any driver that needs to regularly
> allocate dmable pages should really think about doing that at startup,
> and just holding onto these flip buffers for its lifetime.

Any driver using DMA for performance reasons is not going to benefit
from a flip buffer that the CPU needs to copy to provide for userspace
page fragmentation.

Drivers should in the near future be able to DMA directly into
userspace memory. We need to lock down the pages involved, and be able
to send a "list of pages" for the driver to use.....

Roger.