1 #include <fcntl.h>
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include <unistd.h>
5 
6 #include <sys/ioctl.h>
7 #include <sys/mman.h>
8 #include <sys/prctl.h>
9 #include <sys/stat.h>
10 #include <sys/types.h>
11 
12 #include <linux/types.h>
13 
14 #define MB (1UL << 20)
15 #define PAGE_SIZE sysconf(_SC_PAGESIZE)
16 
17 #define GUP_FAST_BENCHMARK	_IOWR('g', 1, struct gup_benchmark)
18 
19 struct gup_benchmark {
20 	__u64 delta_usec;
21 	__u64 addr;
22 	__u64 size;
23 	__u32 nr_pages_per_call;
24 	__u32 flags;
25 };
26 
main(int argc,char ** argv)27 int main(int argc, char **argv)
28 {
29 	struct gup_benchmark gup;
30 	unsigned long size = 128 * MB;
31 	int i, fd, opt, nr_pages = 1, thp = -1, repeats = 1, write = 0;
32 	char *p;
33 
34 	while ((opt = getopt(argc, argv, "m:r:n:tT")) != -1) {
35 		switch (opt) {
36 		case 'm':
37 			size = atoi(optarg) * MB;
38 			break;
39 		case 'r':
40 			repeats = atoi(optarg);
41 			break;
42 		case 'n':
43 			nr_pages = atoi(optarg);
44 			break;
45 		case 't':
46 			thp = 1;
47 			break;
48 		case 'T':
49 			thp = 0;
50 			break;
51 		case 'w':
52 			write = 1;
53 		default:
54 			return -1;
55 		}
56 	}
57 
58 	gup.nr_pages_per_call = nr_pages;
59 	gup.flags = write;
60 
61 	fd = open("/sys/kernel/debug/gup_benchmark", O_RDWR);
62 	if (fd == -1)
63 		perror("open"), exit(1);
64 
65 	p = mmap(NULL, size, PROT_READ | PROT_WRITE,
66 			MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
67 	if (p == MAP_FAILED)
68 		perror("mmap"), exit(1);
69 	gup.addr = (unsigned long)p;
70 
71 	if (thp == 1)
72 		madvise(p, size, MADV_HUGEPAGE);
73 	else if (thp == 0)
74 		madvise(p, size, MADV_NOHUGEPAGE);
75 
76 	for (; (unsigned long)p < gup.addr + size; p += PAGE_SIZE)
77 		p[0] = 0;
78 
79 	for (i = 0; i < repeats; i++) {
80 		gup.size = size;
81 		if (ioctl(fd, GUP_FAST_BENCHMARK, &gup))
82 			perror("ioctl"), exit(1);
83 
84 		printf("Time: %lld us", gup.delta_usec);
85 		if (gup.size != size)
86 			printf(", truncated (size: %lld)", gup.size);
87 		printf("\n");
88 	}
89 
90 	return 0;
91 }
92