papi_hw_int.c

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/* This file attempts to test the PAPI_HW_INT               */
/* performance counter (Total hardware interrupts).         */

/* This assumes that interrupts will be happening in the background */
/* Including a regular timer tick of HZ.  This is not always true   */
/* but should be roughly true on your typical Linux system.         */

/* 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"


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

    int quiet;

    long long count;
    int retval;
    int eventset=PAPI_NULL;

    struct timespec before,after;
    unsigned long long seconds;
        unsigned long long ns;

    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_HW_INT\n");
    }

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

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

    /********************************/
    /* testing 3 seconds of runtime */
    /********************************/

    if (!quiet) {
        printf("\nRunning for 3 seconds\n");
    }

    clock_gettime(CLOCK_REALTIME,&before);

    PAPI_reset(eventset);
    PAPI_start(eventset);

    while(1) {
        clock_gettime(CLOCK_REALTIME,&after);

        seconds=after.tv_sec - before.tv_sec;
        ns = after.tv_nsec - before.tv_nsec;
        ns = (seconds*1000000000ULL)+ns;

        /* be done if 3 billion nanoseconds has passed */
        if (ns>3000000000ULL) break;
    }

    retval=PAPI_stop(eventset,&count);

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

    if (!quiet) {
        printf("\tMeasured interrupts = %lld\n",count);
        /* FIXME: find actua Hz on system */
        /* Or even, read /proc/interrupts */
        printf("\tAssuming HZ=250, expect roughly 750\n");
    }

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

    if (count<10) {
        if (!quiet) printf("Too few interrupts!\n");
        test_fail( __FILE__, __LINE__, "Too few interrupts!", 1 );
    }

    test_pass( __FILE__ );

    return 0;
}