tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#include <linux/kernel.h>
2#include <linux/mm.h>
3#include <linux/slab.h>
4#include <linux/uaccess.h>
5#include <linux/ktime.h>
6#include <linux/debugfs.h>
7
8#define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_benchmark)
9#define GUP_LONGTERM_BENCHMARK _IOWR('g', 2, struct gup_benchmark)
10#define GUP_BENCHMARK _IOWR('g', 3, struct gup_benchmark)
11
12struct gup_benchmark {
13 __u64 get_delta_usec;
14 __u64 put_delta_usec;
15 __u64 addr;
16 __u64 size;
17 __u32 nr_pages_per_call;
18 __u32 flags;
19 __u64 expansion[10]; /* For future use */
20};
21
22static int __gup_benchmark_ioctl(unsigned int cmd,
23 struct gup_benchmark *gup)
24{
25 ktime_t start_time, end_time;
26 unsigned long i, nr_pages, addr, next;
27 int nr;
28 struct page **pages;
29
30 if (gup->size > ULONG_MAX)
31 return -EINVAL;
32
33 nr_pages = gup->size / PAGE_SIZE;
34 pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
35 if (!pages)
36 return -ENOMEM;
37
38 i = 0;
39 nr = gup->nr_pages_per_call;
40 start_time = ktime_get();
41 for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
42 if (nr != gup->nr_pages_per_call)
43 break;
44
45 next = addr + nr * PAGE_SIZE;
46 if (next > gup->addr + gup->size) {
47 next = gup->addr + gup->size;
48 nr = (next - addr) / PAGE_SIZE;
49 }
50
51 switch (cmd) {
52 case GUP_FAST_BENCHMARK:
53 nr = get_user_pages_fast(addr, nr, gup->flags & 1,
54 pages + i);
55 break;
56 case GUP_LONGTERM_BENCHMARK:
57 nr = get_user_pages(addr, nr,
58 (gup->flags & 1) | FOLL_LONGTERM,
59 pages + i, NULL);
60 break;
61 case GUP_BENCHMARK:
62 nr = get_user_pages(addr, nr, gup->flags & 1, pages + i,
63 NULL);
64 break;
65 default:
66 return -1;
67 }
68
69 if (nr <= 0)
70 break;
71 i += nr;
72 }
73 end_time = ktime_get();
74
75 gup->get_delta_usec = ktime_us_delta(end_time, start_time);
76 gup->size = addr - gup->addr;
77
78 start_time = ktime_get();
79 for (i = 0; i < nr_pages; i++) {
80 if (!pages[i])
81 break;
82 put_page(pages[i]);
83 }
84 end_time = ktime_get();
85 gup->put_delta_usec = ktime_us_delta(end_time, start_time);
86
87 kvfree(pages);
88 return 0;
89}
90
91static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
92 unsigned long arg)
93{
94 struct gup_benchmark gup;
95 int ret;
96
97 switch (cmd) {
98 case GUP_FAST_BENCHMARK:
99 case GUP_LONGTERM_BENCHMARK:
100 case GUP_BENCHMARK:
101 break;
102 default:
103 return -EINVAL;
104 }
105
106 if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
107 return -EFAULT;
108
109 ret = __gup_benchmark_ioctl(cmd, &gup);
110 if (ret)
111 return ret;
112
113 if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
114 return -EFAULT;
115
116 return 0;
117}
118
119static const struct file_operations gup_benchmark_fops = {
120 .open = nonseekable_open,
121 .unlocked_ioctl = gup_benchmark_ioctl,
122};
123
124static int gup_benchmark_init(void)
125{
126 debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
127 &gup_benchmark_fops);
128
129 return 0;
130}
131
132late_initcall(gup_benchmark_init);