Hi Ole, Eugene
For what it is worth, I tried Ole's program here,
as Devendra Rai had done before.
I ran it across two nodes, with a total of 16 processes.
I tried mca parameters for openib Infiniband,
then for tcp on Gigabit Ethernet.
Both work.
I am using OpenMPI 1.4.3 compiled with GCC 4.1.2 on
Hi Eugene
You're right, it is blocking send, buffers can be reused after MPI_Send
returns.
My bad, I only read your answer to Sebastien and Ole
after I posted mine.
Could MPI run out of [internal] buffers to hold the messages, perhaps?
The messages aren't that big anyway [5000 doubles].
Could
Hi Ole
You could try the examples/connectivity.c program in the
OpenMPI source tree, to test if everything is alright.
It also hints how to solve the buffer re-use issue
that Sebastien [rightfully] pointed out [i.e., declare separate
buffers for MPI_Send and MPI_Recv].
Gus Correa
Sébastien Bois
Should be fine. Once MPI_Send returns, it should be safe to reuse the
buffer. In fact, the return of the call is the only way you have of
checking that the message has left the user's send buffer. The case
you're worried about is probably MPI_Isend, where you have to check
completion with an
Hello,
Is it safe to re-use the same buffer (variable A) for MPI_Send and MPI_Recv
given that MPI_Send may be eager depending on
the MCA parameters ?
>
>
> Sébastien
>
> De : users-boun...@open-mpi.org [users-boun...@open-mpi.org] de la part de
> Ole
