On Wed, Oct 10, 2018 at 8:20 PM Dan Cross <cro...@gmail.com> wrote: >> don't forget the code complexity with dealing with these scattered >> pages in the *DRIVERS*. > > It's really not that hard. The way Linux does it is pretty bad, but it's not > like that's the only way to do it.
SunOS and Win32 (believe it or not) managed to get this "right"; dealing with zero-copy in those kernels was a non-event. I'm not sure I understand the assertion how this would affect constituent drivers. This sort of detail is handled at a higher level - the driver generally operates on a buffer that gets jammed into a ring for DMA transfer. Apart from grabbing the physical address, the worst you may have to do is pin/unpin the block for the DMA operation. From the driver's perspective, it's memory. It doesn't matter where it came from (or who owns it for that matter). > Or don't. There's a lot to be said for keeping it simple...
