1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <string.h>
4 #include <pthread.h>
5
6 static struct thread_data {
7 unsigned long mib;
8 } td;
9
worker(void * data)10 static void *worker(void *data)
11 {
12 struct thread_data *td = data;
13 unsigned long index;
14 size_t size;
15 char *buf;
16 int i, first = 1;
17
18 size = td->mib * 1024UL * 1024UL;
19 buf = malloc(size);
20
21 for (i = 0; i < 100000; i++) {
22 for (index = 0; index + 4096 < size; index += 4096)
23 memset(&buf[index+512], 0x89, 512);
24 if (first) {
25 printf("loop%d: did %lu MiB\n", i+1, size/(1024UL*1024UL));
26 first = 0;
27 }
28 }
29 return NULL;
30 }
31
main(int argc,char * argv[])32 int main(int argc, char *argv[])
33 {
34 unsigned long mib, threads;
35 pthread_t *pthreads;
36 int i;
37
38 if (argc < 3) {
39 printf("%s: <MiB per thread> <threads>\n", argv[0]);
40 return 1;
41 }
42
43 mib = strtoul(argv[1], NULL, 10);
44 threads = strtoul(argv[2], NULL, 10);
45
46 pthreads = calloc(threads, sizeof(pthread_t));
47 td.mib = mib;
48
49 for (i = 0; i < threads; i++)
50 pthread_create(&pthreads[i], NULL, worker, &td);
51
52 for (i = 0; i < threads; i++) {
53 void *ret;
54
55 pthread_join(pthreads[i], &ret);
56 }
57 return 0;
58 }
59