[OMPI users] locations of processes spawned by MPI_Comm_spawn

2007-08-15 Thread Isaac Huang
Hello, I've observed the following things about locations of spawned processes by running a simple program, please correct me if anything is wrong: 1. the default policy seems to be byslot, and specifying bynode in mpirun command line can change that. 2. the order of hosts in the hostfile is use

[OMPI users] end-to-end data reliability

2007-07-16 Thread Isaac Huang
Hello, I read from the FAQ that current Open MPI releases don't support end-to-end data reliability. But I still have some confusing that can't be solved by googling or reading the FAQ: 1. I read from "MPI - The Complete Reference" that "MPI provides the user with reliable message transmission. A

[OMPI users] read send buffer before a send operation completes

2007-07-12 Thread Isaac Huang
It's prohibited by the standard to read send buffer before a send operation completes, and I understand the theoretical rationale behind it. I'm currently layering a protocol stack on top of MPI, and this protocol allows a buffer to be read by multiple peers concurrently. Thus for strict conforma