> I am wondering whether we need contiguous memory for a PHYSICAL buffer to > perform the DMA I/O.
yes. The DMA request should either not cross a physical page or if the request does cross a physical page, those pages must be contiguous. the exception to this is if your DMA card has a memory management unit, and you are sharing the same virtual to physical map with the MMU and the host memory allocation space (for a driver, the kernel physical map). --mark tinguely. To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-hackers" in the body of the message
