% mpicc -o pingpong pingpong.c 
% mpirun -np 2 pingpong
Kind		n	time (sec)	Rate (MB/sec)
Send/Recv	1	0.003574	0.002238
Send/Recv	2	0.003592	0.004455
Send/Recv	4	0.003603	0.008882
Send/Recv	8	0.003621	0.017675
Send/Recv	16	0.003678	0.034803
Send/Recv	32	0.003709	0.069020
Send/Recv	64	0.003735	0.137084
Send/Recv	128	0.004264	0.240178
Send/Recv	256	0.005268	0.388799
Send/Recv	512	0.007890	0.519171
Send/Recv	1024	0.011941	0.686011
Send/Recv	2048	0.021438	0.764250
Send/Recv	4096	0.038588	0.849165
Send/Recv	8192	0.077029	0.850802
Send/Recv	16384	0.146270	0.896096
Send/Recv	32768	0.287323	0.912367
Send/Recv	65536	0.575686	0.910719
Send/Recv	131072	1.193515	0.878562
Send/Recv	262144	2.309940	0.907882
Send/Recv	524288	4.651385	0.901732
p0_26008:  p4_error: interrupt SIGINT: 2
p0_26008:  p4_error: interrupt SIGINT: 2
bm_list_26009:  p4_error: interrupt SIGINT: 2