measure_tlbs.c   [plain text]

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <setjmp.h>
#include <mach/mach.h>
#include <mach/mach_vm.h>
#include <time.h>

#define SUPERPAGE_SIZE (2*1024*1024)
#define SUPERPAGE_MASK (-SUPERPAGE_SIZE)
#define SUPERPAGE_ROUND_UP(a) ((a + SUPERPAGE_SIZE-1) & SUPERPAGE_MASK)

#define RUNS0 100000
#define STEP 4 /* KB */
#define START STEP
#define MAX (1024*1024) /* KB */

#define RUNS1 RUNS0
#define RUNS2 (RUNS0/20)

clock_t
testt(boolean_t superpages, int mode, int write, int kb) {
	static int sum;
	char *data;
	unsigned int run, p, p2, i, res;
	mach_vm_address_t addr = 0;
	int pages = kb/4;
	mach_vm_size_t	size = SUPERPAGE_ROUND_UP(pages*PAGE_SIZE); /* allocate full superpages */
	int kr;

	kr = mach_vm_allocate(mach_task_self(), &addr, size, VM_FLAGS_ANYWHERE | (superpages? VM_FLAGS_SUPERPAGE_SIZE_2MB : VM_FLAGS_SUPERPAGE_NONE));

	if (!addr)
		return 0;

	data = (char*)(long)addr;

	/* touch every base page to make sure everything is mapped and zero-filled */
	for (p = 0; p<pages; p++) {
		sum += data[p*PAGE_SIZE];
	}

	clock_t a = clock(); /* start timing */
	switch (mode) {
		case 0:	/* one byte every 4096 */
			if (write) {
				for (run = 0; run < RUNS0; run++) {
					for (p = 0; p<pages; p++) {
						data[p*PAGE_SIZE] = run & 0xFF;
					}
				}
			} else {
				for (run = 0; run < RUNS0; run++) {
					for (p = 0; p<pages; p++) {
						sum += data[p*PAGE_SIZE];
					}
				}
			}
			break;
		case 1:	/* every byte */
			if (write) {
				for (run = 0; run < RUNS1/PAGE_SIZE; run++) {
					for (i = 0; i<pages*PAGE_SIZE; i++) {
						data[i] = run & 0xFF;
					}
				}
			} else {
				for (run = 0; run < RUNS1/PAGE_SIZE; run++) {
					for (i = 0; i<pages*PAGE_SIZE; i++) {
						sum += data[i];
					}
				}
			}
			break;
		case 2:	/* random */
#define PRIME 15485863
#define NODE_SIZE 128		/* bytes per node */
#define NODE_ACCESSES 16	/* accesses per node */
			p = 0;
			if (write) {
				for (run = 0; run < RUNS2*pages; run++) {
					p += PRIME;
					p2 = p % (pages*PAGE_SIZE/NODE_SIZE);
//printf("p2 = %d\n", p2);
					for (i = 0; i < NODE_ACCESSES; i++) {
						data[p2*NODE_SIZE+i] = run & 0xFF;
					}
				}
			} else {
				for (run = 0; run < RUNS2*pages; run++) {
					p += PRIME;
					p2 = p % (pages*PAGE_SIZE/NODE_SIZE);
					for (i = 0; i < NODE_ACCESSES; i++) {
						sum += data[p2*NODE_SIZE+i];
					}
				}
			}
			break;
	}
	clock_t b = clock(); /* stop timing */
	mach_vm_deallocate(mach_task_self(), addr, size);
	res = b-a;
	res /= pages;
	return res;
}

int main(int argc, char **argv) {
	int kb;
	uint64_t time1, time2, time3, time4;

	int mode;

	printf("; m0 r s; m0 r b; m0 w s; m0 w b; m1 r s; m1 r b; m1 w s; m1 w b; m2 r s; m2 r b; m2 w s; m2 w b\n");
	for (kb=START; kb<MAX; kb+=STEP) {
		printf("%d", kb);
		for (mode=0; mode<=2; mode++) {
			time1=time2=time3=time4=-1;
			time1 = testt(TRUE, mode, 0, kb);	// read super
			time2 = testt(FALSE, mode, 0, kb);	// read base
			time3 = testt(TRUE, mode, 1, kb);	// write super
			time4 = testt(FALSE, mode, 1, kb);	// write base
			printf("; %lld; %lld; %lld; %lld", time1, time2, time3, time4);
			fflush(stdout);
		}
		printf("\n");
	}

	return 0;
}