On Oct 29, 2006, at 1:49 AM, David Young wrote:
You must pad struct rtk_desc to the cacheline size to avoid cacheline interference. I cannot emphasize enough how important that is!
That only works for devices which provide a "next descriptor" address in the descriptor itself. Not all devices do (they assume a packed ring, or something).
That said...
bus_dma really ought to provide a #define for the machine's cacheline size.
...yes, bus_dma really should provide a function that returns this value.
-- thorpej