/* This code attempts to test the L2 Data Cache Missses		*/

/* performance counter PAPI_L2_DCM				*/

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

/* Due to prefetching it is hard to create a testcase short of */

/* just having random accesses. */

/* In addition, due to context switching the cache might be */

/* affected by other processes on a busy system. */

/* Other tests to attempt */

/* Repeatedly reading same cache line should give very small error */

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include "papi.h"

#include "papi_test.h"

#include "cache_helper.h"

#include "display_error.h"

#include "testcode.h"

/* How much should we allow? */

#define ALLOWED_ERROR	5.0

#define NUM_RUNS	100

#define ITERATIONS	1000000

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

	int i;

	int eventset=PAPI_NULL;

	int num_runs=NUM_RUNS;

	long long high,low,average,expected;

	long long count,total;

	int retval;

	int l1_size,l2_size,l1_linesize,l2_linesize,l2_entries;

	int arraysize;

	int quiet,errors=0;

	double error;

	double *array;

	double aSumm = 0.0;

	quiet=tests_quiet(argc,argv);

	if (!quiet) {

		printf("Testing the PAPI_L2_DCM event\n");

	}

	/* Init the PAPI library */

	retval = PAPI_library_init(PAPI_VER_CURRENT);

	if (retval != PAPI_VER_CURRENT) {

		test_fail(__FILE__,__LINE__,"PAPI_library_init",retval);

	}

	retval=PAPI_create_eventset(&eventset);

	if (retval!=PAPI_OK) {

		test_fail( __FILE__, __LINE__, "PAPI_create_eventset", retval );

	}

	retval=PAPI_add_named_event(eventset,"PAPI_L2_DCM");

	if (retval!=PAPI_OK) {

		test_skip( __FILE__, __LINE__, "adding PAPI_L2_DCM", retval );

	}

	l1_size=get_cachesize(L1D_CACHE);

	l1_linesize=get_linesize(L1D_CACHE);

	l2_size=get_cachesize(L2_CACHE);

	l2_linesize=get_linesize(L2_CACHE);

	l2_entries=get_entries(L2_CACHE);

	if (!quiet) {

		printf("\tDetected %dk L1 DCache, %dB linesize\n",

			l1_size/1024,l1_linesize);

		printf("\tDetected %dk L2 DCache, %dB linesize, %d entries\n",

			l2_size/1024,l2_linesize,l2_entries);

	}

	arraysize=(l2_size/sizeof(double))*8;

	if (arraysize==0) {

		if (!quiet) printf("Could not detect cache size\n");

		test_skip(__FILE__,__LINE__,"Could not detect cache size",0);

	}

	if (!quiet) {

		printf("\tAllocating %zu bytes of memory (%d doubles)\n",

			arraysize*sizeof(double),arraysize);

	}

	array=calloc(arraysize,sizeof(double));

	if (array==NULL) {

		test_fail(__FILE__,__LINE__,"Can't allocate memory",0);

	}

	/******************/

	/* Testing Writes */

	/******************/

	if (!quiet) {

		printf("\nWrite Test: Writing an array of %d doubles %d random times:\n",

			arraysize,ITERATIONS);

		printf("\tPrefetch and shared nature of L2s make this hard.\n");

		printf("\tExpected 7/8 of accesses to be miss.\n");

        }

	high=0; low=0; total=0;

	for(i=0;i

		PAPI_reset(eventset);

		PAPI_start(eventset);

		cache_random_write_test(array,arraysize,ITERATIONS);

		retval=PAPI_stop(eventset,&count);

		if (retval!=PAPI_OK) {

			test_fail( __FILE__, __LINE__,

				"reading PAPI_L2_DCM", retval );

		}

		if (count>high) high=count;

		if ((low==0) || (count

		total+=count;

	}

	average=(total/num_runs);

	expected=(ITERATIONS*7)/8;

//	expected=arraysize/(l1_linesize);

	error=display_error(average,high,low,expected,quiet);

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

		if (!quiet) {

			printf("Instruction count off by more "

				"than %.2lf%%\n",ALLOWED_ERROR);

		}

		errors++;

	}

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

	/******************/

	/* Testing Reads  */

	/******************/

	if (!quiet) {

		printf("\nRead Test: Summing %d random doubles from array "

			"of size %d:\n",ITERATIONS,arraysize);

		printf("\tExpected 7/8 of accesses to be miss.\n");

        }

	high=0; low=0; total=0;

	for(i=0;i

		PAPI_reset(eventset);

		PAPI_start(eventset);

		aSumm+=cache_random_read_test(array,arraysize,ITERATIONS);

		retval=PAPI_stop(eventset,&count);

		if (retval!=PAPI_OK) {

			test_fail( __FILE__, __LINE__,

				"reading PAPI_L2_DCM", retval );

		}

		if (count>high) high=count;

		if ((low==0) || (count

		total+=count;

	}

	average=(total/num_runs);

	expected=(ITERATIONS*7)/8;

//	expected=arraysize/(l1_linesize/sizeof(double));

	error=display_error(average,high,low,expected,quiet);

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

		if (!quiet) {

			printf("Instruction count off by more "

				"than %.2lf%%\n",ALLOWED_ERROR);

		}

		errors++;

	}

	if (!quiet) {

		printf("\n");

	}

	/* FIXME: Warn, as we fail on broadwell and more recent chips */

	if (errors) {

		test_warn( __FILE__, __LINE__, "Error too high", 1 );

	}

	test_pass(__FILE__);

	return 0;

}