Dear Antonio, Thank you for your fast answering. Do you know how to disable this "active polling" ? Greetings, Philip Von: [email protected] [mailto:[email protected]] Im Auftrag von "Antonio J. Peña" Gesendet: Dienstag, 1. Juli 2014 16:30 An: [email protected] Betreff: Re: [mpich-discuss] Time distribution of Intel MPI Benchmark (PingPong) Dear Philip, Both functions are part of MPICH. MPICH uses intentionally active polling to minimize the latency on communications. In short, you get faster communications by repeatedly checking for communication completion during waiting times. So, that's expected. Antonio On 07/01/2014 09:16 AM, Klaus Philip wrote: Hi, I tested mpich2 3.1.1 with the Intel MPI Benchmark, more precisely the "PingPong"-Benchmark. It uses the MPI_Send and MPI_Recv function to send one message from Process 1 to Process 2 and back. While the benchmark was running, I executed the Sysprofiler (sysprof) to check the time distribution (Picture below). My question is now, if the two marked Processes (MPID_nem_lmt_shm_progress and poll) are parts of MPICH or the Intel-PingPong-Benchmark, because they are both consuming much time (49,03% and 19,99%). [cid:[email protected]] Greetings, Philip _______________________________________________ discuss mailing list [email protected]<mailto:[email protected]> To manage subscription options or unsubscribe: https://lists.mpich.org/mailman/listinfo/discuss -- Antonio J. Peña Postdoctoral Appointee Mathematics and Computer Science Division Argonne National Laboratory 9700 South Cass Avenue, Bldg. 240, Of. 3148 Argonne, IL 60439-4847 [email protected]<mailto:[email protected]> www.mcs.anl.gov/~apenya<http://www.mcs.anl.gov/~apenya>