www.pudn.com > pebble.zip > lat_cache.c

/*  
 * Copyright 1999, 2000, 2001, 2002 Lucent Technologies Inc. 
 * All Rights Reserved. 
 * Information Sciences Research Center, Bell Labs. 
 * 
 * LUCENT TECHNOLOGIES DOES NOT CLAIM MERCHANTABILITY OF THIS SOFTWARE  
 * OR THE SUITABILITY OF THIS SOFTWARE FOR ANY PARTICULAR PURPOSE. The 
 * software is provided "as is" without expressed or implied warranty  
 * of any kind. 
 * 
 * These notices must be retained in any copies of any part of this 
 * software. 
 * 
 */ 
 
#include "pebble.h" 
#include "unistd.h" 
#include "types.h" 
#include "time.h" 
#include "synch.h" 
#include "perfcount.h" 
 
#define MEM_START       0 
#define MEM_SIZE        4*1024*1024 
#define SMALLEST_SIZE   8*1024 
#define CACHE_LINE      32 
 
int 
main(void) 
{ 
 
	volatile char *p, *end; 
	char *area; 
	volatile int *q; 
	int i, ntimes; 
	int size, sum; 
	int perf_ix; 
	uint perf_count; 
	uvlong start_time, elapsed; 
 
	printf("lat_cache benchmark starting\n"); 
 
	if ((int)(area = (char *)sbrk(MEM_SIZE)) <= 0) 
		panic("sbrk failed:"); 
 
	/* a quick memory test */ 
	end = area + MEM_SIZE; 
	for (q = (int *)area; q < (int *)end; q++) 
		*q = (int)q; 
 
	for (q = (int *)area; q < (int *)end; q++) 
		if (*q != (int)q) { 
			printf("memory test failed for address %08x = %08x\n", 
				(uint)q, *q); 
			task_exit(1); 
		} 
 
	for (size = SMALLEST_SIZE; size <= MEM_SIZE; size <<= 1) { 
		printf("=============\n"); 
		printf("testing memory scan of %d bytes area\n", size); 
 
		ntimes = MEM_SIZE / size; 
		sum = 0; 
 
		/* initial scan to fill the cache */ 
		end = area + size; 
		for (p = area; p < end; p += CACHE_LINE) 
		        sum += *p; 
 
		for (perf_ix = 0; perf_vec[perf_ix].name != NULL; perf_ix++) { 
 
			set_perf_ctrl(perf_vec[perf_ix].ctrl); 
			start_time = hrtime(); 
 
			for (i = 0; i < ntimes; i++) { 
				for (p = area; p < end; p += CACHE_LINE) 
					sum += *p; 
			} 
 
			perf_count = get_perf_count(); 
			elapsed = 2 * (hrtime() - start_time); 
 
			printf("%s: %d elapsed time: %d cycles (%d cycles/access) sum=%d\n", 
				perf_vec[perf_ix].name, perf_count, 
				(int)elapsed, 
				(int)(elapsed / (MEM_SIZE/CACHE_LINE)), 
				sum); 
		} 
	} 
 
	printf("LAT_CACHE ENDED\n"); 
	task_exit(0); 
	return(1); 
}