mm/gup_benchmark.c: add additional pinning methods
[muen/linux.git] / mm / gup_benchmark.c
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
12 struct 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
22 static 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         nr_pages = gup->size / PAGE_SIZE;
31         pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
32         if (!pages)
33                 return -ENOMEM;
34
35         i = 0;
36         nr = gup->nr_pages_per_call;
37         start_time = ktime_get();
38         for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
39                 if (nr != gup->nr_pages_per_call)
40                         break;
41
42                 next = addr + nr * PAGE_SIZE;
43                 if (next > gup->addr + gup->size) {
44                         next = gup->addr + gup->size;
45                         nr = (next - addr) / PAGE_SIZE;
46                 }
47
48                 switch (cmd) {
49                 case GUP_FAST_BENCHMARK:
50                         nr = get_user_pages_fast(addr, nr, gup->flags & 1,
51                                                  pages + i);
52                         break;
53                 case GUP_LONGTERM_BENCHMARK:
54                         nr = get_user_pages_longterm(addr, nr, gup->flags & 1,
55                                                      pages + i, NULL);
56                         break;
57                 case GUP_BENCHMARK:
58                         nr = get_user_pages(addr, nr, gup->flags & 1, pages + i,
59                                             NULL);
60                         break;
61                 default:
62                         return -1;
63                 }
64
65                 if (nr <= 0)
66                         break;
67                 i += nr;
68         }
69         end_time = ktime_get();
70
71         gup->get_delta_usec = ktime_us_delta(end_time, start_time);
72         gup->size = addr - gup->addr;
73
74         start_time = ktime_get();
75         for (i = 0; i < nr_pages; i++) {
76                 if (!pages[i])
77                         break;
78                 put_page(pages[i]);
79         }
80         end_time = ktime_get();
81         gup->put_delta_usec = ktime_us_delta(end_time, start_time);
82
83         kvfree(pages);
84         return 0;
85 }
86
87 static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
88                 unsigned long arg)
89 {
90         struct gup_benchmark gup;
91         int ret;
92
93         switch (cmd) {
94         case GUP_FAST_BENCHMARK:
95         case GUP_LONGTERM_BENCHMARK:
96         case GUP_BENCHMARK:
97                 break;
98         default:
99                 return -EINVAL;
100         }
101
102         if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
103                 return -EFAULT;
104
105         ret = __gup_benchmark_ioctl(cmd, &gup);
106         if (ret)
107                 return ret;
108
109         if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
110                 return -EFAULT;
111
112         return 0;
113 }
114
115 static const struct file_operations gup_benchmark_fops = {
116         .open = nonseekable_open,
117         .unlocked_ioctl = gup_benchmark_ioctl,
118 };
119
120 static int gup_benchmark_init(void)
121 {
122         void *ret;
123
124         ret = debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
125                         &gup_benchmark_fops);
126         if (!ret)
127                 pr_warn("Failed to create gup_benchmark in debugfs");
128
129         return 0;
130 }
131
132 late_initcall(gup_benchmark_init);