Assignment 8: ENERGY group

Assignment 8: ENERGY group

by Arjun Lenan Sandhya -
Number of replies: 2

I ran the pi by integration benchmark with the ENERGY group specific but it seems like only one of the core is actually consuming energy. Following is the output I received.











Is this expected? Following is the code inside I have in my batch script.

icx -O3 -xHost -qopenmp -DLIKWID_PERFMON $LIKWID_INC parallelpi.c time.c $LIKWID_LIB -llikwid
srun --cpu-freq=2400000-2400000 likwid-perfctr -C S0:0-3 -g ENERGY -m ./a.out

Relevant snippet of the source code:
    LIKWID_MARKER_INIT;
#pragma omp parallel
{
    LIKWID_MARKER_REGISTER("pi");
}
    wcTimeStart = getTimeStamp();
#pragma omp parallel
{
    LIKWID_MARKER_START("pi");
    #pragma omp for reduction(+:sum) private(x)
    for (int i=0; i<slices; i++){
        double x = (i+0.5)*delta_x;
        sum = sum + 4*sqrt(1.0-x*x);
    }
    LIKWID_MARKER_STOP("pi");
}
    wcTimeEnd = getTimeStamp();
    LIKWID_MARKER_CLOSE;
Any help would be appreciated smile


In reply to Arjun Lenan Sandhya

Re: Assignment 8: ENERGY group

by Jan Laukemann -
The energy is measured via the RAPL interface and only enables to monitor the consumed energy on a package-level, i.e., socket-level.
This means, you will always only get values on core 0 and core 36 on a Fritz node and these numbers account for the whole socket (0-35, 36-71).