[Beowulf] TOE on Linux?

[Greg Lindahl]

On Tue, May 20, 2008 at 03:10:23PM -0400, Mark Hahn wrote:

> but do you imply that IB RDMA is being used to provide the kind of network
> shared-memory I described?  that is, not put/get, but an area which is 
> accessed directly as if it's local memory,

There is no such thing in the IB spec.

It's usually called "reflexive memory" in the literature, and a few
systems have provided it: SCI, Digital's Memory Channel. (Not
counting, of course, coherant memory systems like Altix.) You still
have to coordinate accessing and updating the memory in some fashion,
and you don't get to control the size of messages.

> is the vendor you're talking about ScaleMP?

ScaleMP sure looks like ordinary software distributed shared memory,
which probaby leads to the lack of published benchmarks: SDSM is known
to not work so well.

-- greg