On Mon, 18 Mar 2013 11:49:40 +0100 Norman Feske (NF) wrote:

[Details snipped]

NF> What do you think? Would the vcore idea be worthwhile to explore? Those
NF> of you experienced in the field of manycore NUMA systems, do you see
NF> additional pitfalls? Or even better, does anyone has alternative ideas
NF> to explore? Also, I am very interested in ways to validate work in this
NF> domain. How can we measure our success?

There are also use cases where you don't want to partition. One example is a
multi-core VM, where each virtual CPU could run on a different physical core
and yet all of those virtual CPUs share the same memory.

Rather than going for an extreme design point, where virtually nothing is
shared (e.g., Barrelfish), I think it would be better to provide an
interface where the user has precise control over what is shared and what
isn't.

I'd go for concurrent invocation of services first. Then you'll know what
data structures you have contention on. And then you can decide whether you
want that data replicated (read-mostly) or shared (frequently written).

IMHO, dealing with replicas, distributed protocols, consensus and all that
is a lot harder than implementing a few locks or atomic ops on pieces of
shared memory. Especially now that we have HLE and TSX coming really soon.

Cheers,
Udo