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