Re: MPI/RT for Myrinet

Ashish Bijlani wrote:
> On 7/28/05, Patrick Geoffray <[email protected]> wrote:
> 
>>Ashish Bijlani wrote:
>>
>>>Hi People,
>>>
>>>I've a setup of 8 nodes, each having M3F-PCIXD-2 interface. I want to
>>>pass messages in Real-Time using MPI. Does this Myrinet interface
>>>support Real-Time MPI(MPI/RT)?
>>
>>No. MPI/RT never really took off. I don't know anybody using it.
>>
> 
> 
> Can I use MPICH-GM in Real-Time to pass messages to other nodes? If
> not, then what are the bottlenecks involved?

You can use MPICH-GM to pass messages, but you won't have hard real time 
guarantees. First, you need a real time OS, and then you need to have 
policies and admission control and scheduling in the NIC or in the lib 
to guarantee the RT message deliveries. A lot of work.

>>>If not, then how can I pass messages in
>>>Real-Time across nodes?

If your RT deadlines fits in the current best effort performance, you 
have nothing to do, but you have no guarantees either.

Patrick
-- 

Patrick Geoffray
Myricom, Inc.
http://www.myri.com