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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 | #include <linux/kernel.h> #include <linux/mm.h> #include <linux/slab.h> #include <linux/uaccess.h> #include <linux/ktime.h> #include <linux/debugfs.h> #define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_benchmark) #define GUP_BENCHMARK _IOWR('g', 2, struct gup_benchmark) #define PIN_FAST_BENCHMARK _IOWR('g', 3, struct gup_benchmark) #define PIN_BENCHMARK _IOWR('g', 4, struct gup_benchmark) #define PIN_LONGTERM_BENCHMARK _IOWR('g', 5, struct gup_benchmark) struct gup_benchmark { __u64 get_delta_usec; __u64 put_delta_usec; __u64 addr; __u64 size; __u32 nr_pages_per_call; __u32 flags; __u64 expansion[10]; /* For future use */ }; static void put_back_pages(unsigned int cmd, struct page **pages, unsigned long nr_pages) { unsigned long i; switch (cmd) { case GUP_FAST_BENCHMARK: case GUP_BENCHMARK: for (i = 0; i < nr_pages; i++) put_page(pages[i]); break; case PIN_FAST_BENCHMARK: case PIN_BENCHMARK: case PIN_LONGTERM_BENCHMARK: unpin_user_pages(pages, nr_pages); break; } } static void verify_dma_pinned(unsigned int cmd, struct page **pages, unsigned long nr_pages) { unsigned long i; struct page *page; switch (cmd) { case PIN_FAST_BENCHMARK: case PIN_BENCHMARK: case PIN_LONGTERM_BENCHMARK: for (i = 0; i < nr_pages; i++) { page = pages[i]; if (WARN(!page_maybe_dma_pinned(page), "pages[%lu] is NOT dma-pinned\n", i)) { dump_page(page, "gup_benchmark failure"); break; } } break; } } static int __gup_benchmark_ioctl(unsigned int cmd, struct gup_benchmark *gup) { ktime_t start_time, end_time; unsigned long i, nr_pages, addr, next; int nr; struct page **pages; int ret = 0; bool needs_mmap_lock = cmd != GUP_FAST_BENCHMARK && cmd != PIN_FAST_BENCHMARK; if (gup->size > ULONG_MAX) return -EINVAL; nr_pages = gup->size / PAGE_SIZE; pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL); if (!pages) return -ENOMEM; if (needs_mmap_lock && mmap_read_lock_killable(current->mm)) { ret = -EINTR; goto free_pages; } i = 0; nr = gup->nr_pages_per_call; start_time = ktime_get(); for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) { if (nr != gup->nr_pages_per_call) break; next = addr + nr * PAGE_SIZE; if (next > gup->addr + gup->size) { next = gup->addr + gup->size; nr = (next - addr) / PAGE_SIZE; } /* Filter out most gup flags: only allow a tiny subset here: */ gup->flags &= FOLL_WRITE; switch (cmd) { case GUP_FAST_BENCHMARK: nr = get_user_pages_fast(addr, nr, gup->flags, pages + i); break; case GUP_BENCHMARK: nr = get_user_pages(addr, nr, gup->flags, pages + i, NULL); break; case PIN_FAST_BENCHMARK: nr = pin_user_pages_fast(addr, nr, gup->flags, pages + i); break; case PIN_BENCHMARK: nr = pin_user_pages(addr, nr, gup->flags, pages + i, NULL); break; case PIN_LONGTERM_BENCHMARK: nr = pin_user_pages(addr, nr, gup->flags | FOLL_LONGTERM, pages + i, NULL); break; default: ret = -EINVAL; goto unlock; } if (nr <= 0) break; i += nr; } end_time = ktime_get(); /* Shifting the meaning of nr_pages: now it is actual number pinned: */ nr_pages = i; gup->get_delta_usec = ktime_us_delta(end_time, start_time); gup->size = addr - gup->addr; /* * Take an un-benchmark-timed moment to verify DMA pinned * state: print a warning if any non-dma-pinned pages are found: */ verify_dma_pinned(cmd, pages, nr_pages); start_time = ktime_get(); put_back_pages(cmd, pages, nr_pages); end_time = ktime_get(); gup->put_delta_usec = ktime_us_delta(end_time, start_time); unlock: if (needs_mmap_lock) mmap_read_unlock(current->mm); free_pages: kvfree(pages); return ret; } static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) { struct gup_benchmark gup; int ret; switch (cmd) { case GUP_FAST_BENCHMARK: case GUP_BENCHMARK: case PIN_FAST_BENCHMARK: case PIN_BENCHMARK: case PIN_LONGTERM_BENCHMARK: break; default: return -EINVAL; } if (copy_from_user(&gup, (void __user *)arg, sizeof(gup))) return -EFAULT; ret = __gup_benchmark_ioctl(cmd, &gup); if (ret) return ret; if (copy_to_user((void __user *)arg, &gup, sizeof(gup))) return -EFAULT; return 0; } static const struct file_operations gup_benchmark_fops = { .open = nonseekable_open, .unlocked_ioctl = gup_benchmark_ioctl, }; static int gup_benchmark_init(void) { debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL, &gup_benchmark_fops); return 0; } late_initcall(gup_benchmark_init); |