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memprofiletest.c
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/* | |
* memprofiletest | |
* | |
* USAGE: ./memprofiletest size_kb | |
* | |
* eg, ./memprofiletest 10240 # make larger than LLC cache for misses | |
*/ | |
#include <stdio.h> | |
#include <stdlib.h> | |
/* pad methods so they can be LLC profiled without PEBS: */ | |
#define PROF_WORKAROUND | |
void | |
memreader(char *p, unsigned long long j) { | |
char c; | |
c = p[j]; | |
#ifdef PROF_WORKAROUND | |
asm( | |
"mfence\n" | |
"mfence\n" | |
"mfence\n" | |
); | |
#endif | |
} | |
void | |
cachedreader(char *p, unsigned long long j) { | |
char c; | |
c = p[0]; | |
#ifdef PROF_WORKAROUND | |
asm( | |
"mfence\n" | |
"mfence\n" | |
"mfence\n" | |
); | |
#endif | |
} | |
void | |
spinner() { | |
int i, j; | |
for (i = 0, j = 0; i < 100; i++) { | |
j++; | |
} | |
#ifdef PROF_WORKAROUND | |
asm( | |
"mfence\n" | |
"mfence\n" | |
"mfence\n" | |
); | |
#endif | |
} | |
int | |
main(int argc, char *argv[]) | |
{ | |
unsigned long long size, i, j; | |
char *p, c; | |
if (argc != 2) { | |
printf("USAGE: memstride size_KB\n"); | |
exit(1); | |
} | |
size = atoi(argv[1]) * 1024ULL; | |
if ((p = malloc(size)) == NULL) { | |
printf("ERROR: malloc failed\n"); | |
exit(1); | |
} | |
printf("Populate...\n"); | |
for (j = 0; j < size; j += 32) { | |
p[j] = 'a'; | |
} | |
printf("Stride...\n"); | |
i = 0; | |
for (;;) { | |
for (j = 0ULL; j < size; j += 1024) { | |
i++; | |
if (i > 100000000ULL) { exit(0); } | |
memreader(p, j); | |
cachedreader(p, j); | |
spinner(); | |
} | |
} | |
return (0); | |
} |
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