]>
Commit | Line | Data |
---|---|---|
64c349f4 KS |
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 | ||
10 | struct gup_benchmark { | |
11 | __u64 delta_usec; | |
12 | __u64 addr; | |
13 | __u64 size; | |
14 | __u32 nr_pages_per_call; | |
15 | __u32 flags; | |
16 | }; | |
17 | ||
18 | static int __gup_benchmark_ioctl(unsigned int cmd, | |
19 | struct gup_benchmark *gup) | |
20 | { | |
21 | ktime_t start_time, end_time; | |
5ca90cd1 Y |
22 | unsigned long i, nr_pages, addr, next; |
23 | int nr; | |
64c349f4 KS |
24 | struct page **pages; |
25 | ||
15e01792 DC |
26 | if (gup->size > ULONG_MAX) |
27 | return -EINVAL; | |
28 | ||
64c349f4 | 29 | nr_pages = gup->size / PAGE_SIZE; |
cca4fdb1 | 30 | pages = kvzalloc(sizeof(void *) * nr_pages, GFP_KERNEL); |
64c349f4 KS |
31 | if (!pages) |
32 | return -ENOMEM; | |
33 | ||
34 | i = 0; | |
35 | nr = gup->nr_pages_per_call; | |
36 | start_time = ktime_get(); | |
37 | for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) { | |
38 | if (nr != gup->nr_pages_per_call) | |
39 | break; | |
40 | ||
41 | next = addr + nr * PAGE_SIZE; | |
42 | if (next > gup->addr + gup->size) { | |
43 | next = gup->addr + gup->size; | |
44 | nr = (next - addr) / PAGE_SIZE; | |
45 | } | |
46 | ||
47 | nr = get_user_pages_fast(addr, nr, gup->flags & 1, pages + i); | |
cca4fdb1 MT |
48 | if (nr <= 0) |
49 | break; | |
64c349f4 KS |
50 | i += nr; |
51 | } | |
52 | end_time = ktime_get(); | |
53 | ||
54 | gup->delta_usec = ktime_us_delta(end_time, start_time); | |
55 | gup->size = addr - gup->addr; | |
56 | ||
57 | for (i = 0; i < nr_pages; i++) { | |
58 | if (!pages[i]) | |
59 | break; | |
60 | put_page(pages[i]); | |
61 | } | |
62 | ||
63 | kvfree(pages); | |
64 | return 0; | |
65 | } | |
66 | ||
67 | static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd, | |
68 | unsigned long arg) | |
69 | { | |
70 | struct gup_benchmark gup; | |
71 | int ret; | |
72 | ||
73 | if (cmd != GUP_FAST_BENCHMARK) | |
74 | return -EINVAL; | |
75 | ||
76 | if (copy_from_user(&gup, (void __user *)arg, sizeof(gup))) | |
77 | return -EFAULT; | |
78 | ||
79 | ret = __gup_benchmark_ioctl(cmd, &gup); | |
80 | if (ret) | |
81 | return ret; | |
82 | ||
83 | if (copy_to_user((void __user *)arg, &gup, sizeof(gup))) | |
84 | return -EFAULT; | |
85 | ||
86 | return 0; | |
87 | } | |
88 | ||
89 | static const struct file_operations gup_benchmark_fops = { | |
90 | .open = nonseekable_open, | |
91 | .unlocked_ioctl = gup_benchmark_ioctl, | |
92 | }; | |
93 | ||
94 | static int gup_benchmark_init(void) | |
95 | { | |
96 | void *ret; | |
97 | ||
98 | ret = debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL, | |
99 | &gup_benchmark_fops); | |
100 | if (!ret) | |
101 | pr_warn("Failed to create gup_benchmark in debugfs"); | |
102 | ||
103 | return 0; | |
104 | } | |
105 | ||
106 | late_initcall(gup_benchmark_init); |