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