1 #include <linux/kernel.h>
3 #include <linux/slab.h>
4 #include <linux/uaccess.h>
5 #include <linux/ktime.h>
6 #include <linux/debugfs.h>
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)
12 struct gup_benchmark {
17 __u32 nr_pages_per_call;
19 __u64 expansion[10]; /* For future use */
22 static int __gup_benchmark_ioctl(unsigned int cmd,
23 struct gup_benchmark *gup)
25 ktime_t start_time, end_time;
26 unsigned long i, nr_pages, addr, next;
30 nr_pages = gup->size / PAGE_SIZE;
31 pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
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)
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;
49 case GUP_FAST_BENCHMARK:
50 nr = get_user_pages_fast(addr, nr, gup->flags & 1,
53 case GUP_LONGTERM_BENCHMARK:
54 nr = get_user_pages_longterm(addr, nr, gup->flags & 1,
58 nr = get_user_pages(addr, nr, gup->flags & 1, pages + i,
69 end_time = ktime_get();
71 gup->get_delta_usec = ktime_us_delta(end_time, start_time);
72 gup->size = addr - gup->addr;
74 start_time = ktime_get();
75 for (i = 0; i < nr_pages; i++) {
80 end_time = ktime_get();
81 gup->put_delta_usec = ktime_us_delta(end_time, start_time);
87 static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
90 struct gup_benchmark gup;
94 case GUP_FAST_BENCHMARK:
95 case GUP_LONGTERM_BENCHMARK:
102 if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
105 ret = __gup_benchmark_ioctl(cmd, &gup);
109 if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
115 static const struct file_operations gup_benchmark_fops = {
116 .open = nonseekable_open,
117 .unlocked_ioctl = gup_benchmark_ioctl,
120 static int gup_benchmark_init(void)
124 ret = debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
125 &gup_benchmark_fops);
127 pr_warn("Failed to create gup_benchmark in debugfs");
132 late_initcall(gup_benchmark_init);