| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 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 | int ret = 0; |
| 30 | |
| 31 | if (gup->size > ULONG_MAX) |
| 32 | return -EINVAL; |
| 33 | |
| 34 | nr_pages = gup->size / PAGE_SIZE; |
| 35 | pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL); |
| 36 | if (!pages) |
| 37 | return -ENOMEM; |
| 38 | |
| 39 | i = 0; |
| 40 | nr = gup->nr_pages_per_call; |
| 41 | start_time = ktime_get(); |
| 42 | for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) { |
| 43 | if (nr != gup->nr_pages_per_call) |
| 44 | break; |
| 45 | |
| 46 | next = addr + nr * PAGE_SIZE; |
| 47 | if (next > gup->addr + gup->size) { |
| 48 | next = gup->addr + gup->size; |
| 49 | nr = (next - addr) / PAGE_SIZE; |
| 50 | } |
| 51 | |
| 52 | switch (cmd) { |
| 53 | case GUP_FAST_BENCHMARK: |
| 54 | nr = get_user_pages_fast(addr, nr, gup->flags & 1, |
| 55 | pages + i); |
| 56 | break; |
| 57 | case GUP_LONGTERM_BENCHMARK: |
| 58 | nr = get_user_pages(addr, nr, |
| 59 | (gup->flags & 1) | FOLL_LONGTERM, |
| 60 | pages + i, NULL); |
| 61 | break; |
| 62 | case GUP_BENCHMARK: |
| 63 | nr = get_user_pages(addr, nr, gup->flags & 1, pages + i, |
| 64 | NULL); |
| 65 | break; |
| 66 | default: |
| 67 | kvfree(pages); |
| 68 | ret = -EINVAL; |
| 69 | goto out; |
| 70 | } |
| 71 | |
| 72 | if (nr <= 0) |
| 73 | break; |
| 74 | i += nr; |
| 75 | } |
| 76 | end_time = ktime_get(); |
| 77 | |
| 78 | gup->get_delta_usec = ktime_us_delta(end_time, start_time); |
| 79 | gup->size = addr - gup->addr; |
| 80 | |
| 81 | start_time = ktime_get(); |
| 82 | for (i = 0; i < nr_pages; i++) { |
| 83 | if (!pages[i]) |
| 84 | break; |
| 85 | put_page(pages[i]); |
| 86 | } |
| 87 | end_time = ktime_get(); |
| 88 | gup->put_delta_usec = ktime_us_delta(end_time, start_time); |
| 89 | |
| 90 | kvfree(pages); |
| 91 | out: |
| 92 | return ret; |
| 93 | } |
| 94 | |
| 95 | static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd, |
| 96 | unsigned long arg) |
| 97 | { |
| 98 | struct gup_benchmark gup; |
| 99 | int ret; |
| 100 | |
| 101 | switch (cmd) { |
| 102 | case GUP_FAST_BENCHMARK: |
| 103 | case GUP_LONGTERM_BENCHMARK: |
| 104 | case GUP_BENCHMARK: |
| 105 | break; |
| 106 | default: |
| 107 | return -EINVAL; |
| 108 | } |
| 109 | |
| 110 | if (copy_from_user(&gup, (void __user *)arg, sizeof(gup))) |
| 111 | return -EFAULT; |
| 112 | |
| 113 | ret = __gup_benchmark_ioctl(cmd, &gup); |
| 114 | if (ret) |
| 115 | return ret; |
| 116 | |
| 117 | if (copy_to_user((void __user *)arg, &gup, sizeof(gup))) |
| 118 | return -EFAULT; |
| 119 | |
| 120 | return 0; |
| 121 | } |
| 122 | |
| 123 | static const struct file_operations gup_benchmark_fops = { |
| 124 | .open = nonseekable_open, |
| 125 | .unlocked_ioctl = gup_benchmark_ioctl, |
| 126 | }; |
| 127 | |
| 128 | static int gup_benchmark_init(void) |
| 129 | { |
| 130 | debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL, |
| 131 | &gup_benchmark_fops); |
| 132 | |
| 133 | return 0; |
| 134 | } |
| 135 | |
| 136 | late_initcall(gup_benchmark_init); |