papi_tot_cyc.c

Go to the documentation of this file.

/* This file attempts to test the PAPI_TOT_CYC  */
/* performance counter.             */

/* by Vince Weaver, <vincent.weaver@maine.edu>  */


#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <sys/time.h>

#include <time.h>

#include "papi.h"
#include "papi_test.h"

#include "display_error.h"

#include "matrix_multiply.h"

#define SLEEP_RUNS 3


static long long convert_to_ns(struct timespec *before,
                    struct timespec *after) {

    long long seconds;
    long long ns;

    seconds=after->tv_sec - before->tv_sec;
    ns = after->tv_nsec - before->tv_nsec;

    ns = (seconds*1000000000ULL)+ns;

    return ns;
}


int main(int argc, char **argv) {

    int quiet;
    double mmm_ghz;

    double error;

    int i;
    long long count,high=0,low=0,total=0,average=0;
    long long nsecs;
    long long mmm_count;
    long long expected;
    int retval;
    int eventset=PAPI_NULL;

    struct timespec before,after;

    quiet=tests_quiet(argc,argv);

    /* Init the PAPI library */
    retval = PAPI_library_init( PAPI_VER_CURRENT );
    if ( retval != PAPI_VER_CURRENT ) {
        test_fail( __FILE__, __LINE__, "PAPI_library_init", retval );
    }

    if (!quiet) {
        printf("\nTesting PAPI_TOT_CYC\n\n");
    }

    if (!quiet) {
        printf("Testing a sleep of 1 second (%d times):\n",SLEEP_RUNS);
    }

    retval=PAPI_create_eventset(&eventset);
    if (retval!=PAPI_OK) {
        test_fail( __FILE__, __LINE__, "PAPI_create_eventset", retval );
    }

    retval=PAPI_add_named_event(eventset,"PAPI_TOT_CYC");
    if (retval!=PAPI_OK) {
        if (!quiet) printf("Could not add PAPI_TOT_CYC\n");
        test_skip( __FILE__, __LINE__, "adding PAPI_TOT_CYC", retval );
    }


    for(i=0;i<SLEEP_RUNS;i++) {

        PAPI_reset(eventset);
        PAPI_start(eventset);

        sleep(1);

        retval=PAPI_stop(eventset,&count);
        if (retval!=PAPI_OK) {
            test_fail( __FILE__, __LINE__, "PAPI_stop", retval );
        }

        if (count>high) high=count;
        if ((low==0) || (count<low)) low=count;
        total+=count;
    }

    average=total/SLEEP_RUNS;

    if (!quiet) {
        printf("\tAverage should be low, as no user cycles when sleeping\n");
        printf("\tMeasured average: %lld\n",average);
    }

    if (average>100000) {
        if (!quiet) printf("Average cycle count too high!\n");
        test_fail( __FILE__, __LINE__, "idle average", retval );
    }

    /*****************************/
    /* testing Matrix Matrix GHz */
    /*****************************/

    if (!quiet) {
        printf("\nEstimating GHz with matrix matrix multiply\n");
    }

   // We have a problem with subsequent runs requiring fewer cycles than
   // the first run. This may be system dependent; so we do a throw-away
   // run here, so we end up comparing the SECOND run to the 3rd, 4th, etc.

   naive_matrix_multiply(quiet);                // A first run, to init system.

    clock_gettime(CLOCK_REALTIME,&before);

    PAPI_reset(eventset);
    PAPI_start(eventset);

    naive_matrix_multiply(quiet);

    retval=PAPI_stop(eventset,&count);

    if (retval!=PAPI_OK) {
        test_fail( __FILE__, __LINE__, "Problem stopping!", retval );
    }

    clock_gettime(CLOCK_REALTIME,&after);

    nsecs=convert_to_ns(&before,&after);

    mmm_ghz=(double)count/(double)nsecs;

    if (!quiet) {
        printf("\tActual measured cycles = %lld\n",count);
        printf("\tEstimated actual GHz = %.2lfGHz\n",mmm_ghz);
    }

    mmm_count=count;

    /************************************/
    /* Check for Linear Speedup         */
    /************************************/

    if (!quiet) printf("\nTesting for a linear cycle increase\n");

#define REPITITIONS 2

    clock_gettime(CLOCK_REALTIME,&before);

    PAPI_reset(eventset);
    PAPI_start(eventset);

    for(i=0;i<REPITITIONS;i++) {
        naive_matrix_multiply(quiet);
    }

    retval=PAPI_stop(eventset,&count);

    if (retval!=PAPI_OK) {
        test_fail( __FILE__, __LINE__, "Problem stopping!", retval );
    }

    clock_gettime(CLOCK_REALTIME,&after);

    nsecs=convert_to_ns(&before,&after);

    expected=mmm_count*REPITITIONS;

    error=  100.0 * (double)(count-expected) / (double)expected;

    if (!quiet) {
        printf("\tExpected %lld, got %lld\n",expected,count);
        printf("\tError=%.2f%%\n",error);
    }

    if ((error>10.0) || (error<-10.0)) {

        if (!quiet) printf("Error too high!\n");
        test_fail( __FILE__, __LINE__, "Error too high", retval );
    }

    if (!quiet) printf("\n");

    test_pass( __FILE__ );

    return 0;
}