On 25/11/16 06:06 AM, Christian König wrote:
Well Serguei send me a couple of documents about QPI when we started
discuss this internally as well and that's exactly one of the cases I
had in mind when writing this.
If I understood it correctly for such systems P2P is technical possible,
but not necessary a good idea. Usually it is faster to just use a
bouncing buffer when the peers are a bit "father" apart.
That this problem is solved on newer hardware is good, but doesn't helps
us at all if we at want to support at least systems from the last five
years or so.
Well we have been testing with Sandy Bridge, I think the problem was
supposed to be fixed in Ivy but we never tested it so I can't say what
the performance turned out to be. Ivy is nearly 5 years old. I expect
this is something that will be improved more and more with subsequent
A white list may end up being rather complicated if it has to cover
different CPU generations and system architectures. I feel this is a
decision user space could easily make.