Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: 7dd602d7f8db7be0f698021b01d8fc9810d25e5b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/ktime.h>
#include <linux/debugfs.h>

#define GUP_FAST_BENCHMARK	_IOWR('g', 1, struct gup_benchmark)
#define GUP_LONGTERM_BENCHMARK	_IOWR('g', 2, struct gup_benchmark)
#define GUP_BENCHMARK		_IOWR('g', 3, struct gup_benchmark)

struct gup_benchmark {
	__u64 get_delta_usec;
	__u64 put_delta_usec;
	__u64 addr;
	__u64 size;
	__u32 nr_pages_per_call;
	__u32 flags;
	__u64 expansion[10];	/* For future use */
};

static int __gup_benchmark_ioctl(unsigned int cmd,
		struct gup_benchmark *gup)
{
	ktime_t start_time, end_time;
	unsigned long i, nr_pages, addr, next;
	int nr;
	struct page **pages;

	if (gup->size > ULONG_MAX)
		return -EINVAL;

	nr_pages = gup->size / PAGE_SIZE;
	pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
	if (!pages)
		return -ENOMEM;

	i = 0;
	nr = gup->nr_pages_per_call;
	start_time = ktime_get();
	for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
		if (nr != gup->nr_pages_per_call)
			break;

		next = addr + nr * PAGE_SIZE;
		if (next > gup->addr + gup->size) {
			next = gup->addr + gup->size;
			nr = (next - addr) / PAGE_SIZE;
		}

		switch (cmd) {
		case GUP_FAST_BENCHMARK:
			nr = get_user_pages_fast(addr, nr, gup->flags & 1,
						 pages + i);
			break;
		case GUP_LONGTERM_BENCHMARK:
			nr = get_user_pages(addr, nr,
					    (gup->flags & 1) | FOLL_LONGTERM,
					    pages + i, NULL);
			break;
		case GUP_BENCHMARK:
			nr = get_user_pages(addr, nr, gup->flags & 1, pages + i,
					    NULL);
			break;
		default:
			return -1;
		}

		if (nr <= 0)
			break;
		i += nr;
	}
	end_time = ktime_get();

	gup->get_delta_usec = ktime_us_delta(end_time, start_time);
	gup->size = addr - gup->addr;

	start_time = ktime_get();
	for (i = 0; i < nr_pages; i++) {
		if (!pages[i])
			break;
		put_page(pages[i]);
	}
	end_time = ktime_get();
	gup->put_delta_usec = ktime_us_delta(end_time, start_time);

	kvfree(pages);
	return 0;
}

static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
		unsigned long arg)
{
	struct gup_benchmark gup;
	int ret;

	switch (cmd) {
	case GUP_FAST_BENCHMARK:
	case GUP_LONGTERM_BENCHMARK:
	case GUP_BENCHMARK:
		break;
	default:
		return -EINVAL;
	}

	if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
		return -EFAULT;

	ret = __gup_benchmark_ioctl(cmd, &gup);
	if (ret)
		return ret;

	if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
		return -EFAULT;

	return 0;
}

static const struct file_operations gup_benchmark_fops = {
	.open = nonseekable_open,
	.unlocked_ioctl = gup_benchmark_ioctl,
};

static int gup_benchmark_init(void)
{
	debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
				   &gup_benchmark_fops);

	return 0;
}

late_initcall(gup_benchmark_init);