Hi,

I am new user of Open MPI, I've used MPICH before.

There is performance bug with the following scenario:

proc_B:  MPI_Isend(...,proc_A,..,&request)
                   do{
                  sleep(1);
                  MPI_Test(..,&flag,&request);
                  count++
                }while(!flag);

proc_A: MPI_Recv(...,proc_B);

For message size 8MB,  proc_B calls MPI_Test 88 times. It means that point to 
point communication costs 88 seconds.
Btw, bandwidth isn't the problem (interconnection network: InfiniBand)

Obviously, there is the problem with progress of the asynchronous messages.

How can I avoid this problem?
Thank you very much.

Vladimir



      

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