I'm using GPUDirect v1 with Open MPI 1.4.3 and experience blocking MPI_SEND/RECV to block forever.
For two subsequent MPI_RECV, it hangs if the recv buffer pointer of the second recv points to somewhere, i.e. not at the beginning,
in the recv buffer (previously allocated with cudaMallocHost()).
I tried the same with MVAPICH2 and did not see the problem.
Does anybody know about issues with GPUDirect v1 using Open MPI?
Thanks for your help,