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#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <pthread.h>
#include <sched.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/sysinfo.h>
int mode = 0;
int size = 64;
int iterations = 100000;
int num_cpus;
static __inline__ int64_t rdtsc_s(void)
{
unsigned a, d;
asm volatile("cpuid" ::: "%rax", "%rbx", "%rcx", "%rdx");
asm volatile("rdtsc" : "=a" (a), "=d" (d));
return ((unsigned long)a) | (((unsigned long)d) << 32);
}
static __inline__ int64_t rdtsc_e(void)
{
unsigned a, d;
asm volatile("rdtscp" : "=a" (a), "=d" (d));
asm volatile("cpuid" ::: "%rax", "%rbx", "%rcx", "%rdx");
return ((unsigned long)a) | (((unsigned long)d) << 32);
}
static void* test_thread_func(void* arg) {
int64_t clock_before, clock_after;
void* p;
int64_t* clocks = malloc(iterations * sizeof(int64_t));
if (!clocks)
abort();
// set cpu affinity to prevent cpu switching
int64_t tid = (int64_t) arg;
cpu_set_t my_cpu;
/* Skip CPU0 - let the OS run on that one */
int my_cpu_num = (tid % (num_cpus-1))+1;
CPU_ZERO (&my_cpu);
CPU_SET (my_cpu_num, &my_cpu);
if (sched_setaffinity (0, sizeof(my_cpu), &my_cpu) == -1)
perror ("setaffinity failed");
for(int i = 0; i < iterations; i++) {
clock_before = rdtsc_s();
p = malloc(size);
clock_after = rdtsc_e();
// measure potentially cached allocations
if (mode)
free(p);
clocks[i] = clock_after - clock_before;
}
for(int i = 0; i < iterations; i++) {
printf("malloc(%d): %d cycles\n", size, clocks[i]);
}
return NULL;
}
int main(int argc, char* argv[]) {
pthread_t* threads;
int num_threads = 1;
num_cpus = get_nprocs();
if (argc > 5) {
fprintf(stderr, "Usage: %s <iterations> <size> <num threads>\n", argv[0]);
return 1;
}
if (argc > 1) {
if (strncmp(argv[1], "cached", strlen("cached")) == 0) mode = 1;
}
if (argc > 2) iterations = atoi(argv[2]);
if (argc > 3) size = atoi(argv[3]);
if (argc > 4) num_threads = atoi(argv[4]);
fprintf(stderr, "iterations = %d; size = %d; threads = %d\n", iterations, size, num_threads);
threads = (pthread_t*) malloc(num_threads * sizeof(pthread_t));
for (int i = 0; i < num_threads; i++) {
if (0 != pthread_create(&threads[i], NULL, test_thread_func, NULL)) {
perror("pthread_create");
return 1;
}
}
for(int i = 0; i < num_threads; i++) {
if (0 != pthread_join(threads[i], NULL)) {
perror("pthread_join");
return 1;
}
}
return 0;
}
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