Hello, 
I am running a 10,000x10,000 matrix multiplication in 4 processors/1 core and I get the following error:
mpirun -np 4 --hostfile nodes --bynode magic10000

mpirun noticed that job rank1 with PID 635 on node slave1 exited on signal 509(Real-time signal 25).
2 additional process aborted (not shown)
1 process killed (possibly by open MPI)

node file contains:
master
slave1
slave2
slave3