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SubjectRe: Lets get this right (WAS RE:MOSIX and kernel mods)
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: Just how smart have they made this optimisation, BTW? For the volume
: rendering application, you have two conceptual transfers of data: the
: volume data is "shipped" to worker nodes and they in turn "ship"
: subimage data back to the scheduling node.

If I recall correctly, they actually wacked the OS. They used /proc
and made a way that another process could map a different process'
address space. Sends can be implemented, on page sized quantities,
as mapping a page COW into another process' address space.

Zero copy for big data that wasn't touched, otherwise copy on write.

For small data, it was just a copy and a wakeup.

I may have the details wrong, but the bottom line was that MPI went
very, very fast - customers were quite amazed and very pleased. It
exceeded their expectations.

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