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_BENCHMARK _IOWR('g', 2, struct gup_benchmark)
10 #define PIN_FAST_BENCHMARK _IOWR('g', 3, struct gup_benchmark)
11 #define PIN_BENCHMARK _IOWR('g', 4, struct gup_benchmark)
12 #define PIN_LONGTERM_BENCHMARK _IOWR('g', 5, struct gup_benchmark)
14 struct gup_benchmark {
19 __u32 nr_pages_per_call;
21 __u64 expansion[10]; /* For future use */
24 static void put_back_pages(unsigned int cmd, struct page **pages,
25 unsigned long nr_pages)
30 case GUP_FAST_BENCHMARK:
32 for (i = 0; i < nr_pages; i++)
36 case PIN_FAST_BENCHMARK:
38 case PIN_LONGTERM_BENCHMARK:
39 unpin_user_pages(pages, nr_pages);
44 static void verify_dma_pinned(unsigned int cmd, struct page **pages,
45 unsigned long nr_pages)
51 case PIN_FAST_BENCHMARK:
53 case PIN_LONGTERM_BENCHMARK:
54 for (i = 0; i < nr_pages; i++) {
56 if (WARN(!page_maybe_dma_pinned(page),
57 "pages[%lu] is NOT dma-pinned\n", i)) {
59 dump_page(page, "gup_benchmark failure");
67 static int __gup_benchmark_ioctl(unsigned int cmd,
68 struct gup_benchmark *gup)
70 ktime_t start_time, end_time;
71 unsigned long i, nr_pages, addr, next;
76 if (gup->size > ULONG_MAX)
79 nr_pages = gup->size / PAGE_SIZE;
80 pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
85 nr = gup->nr_pages_per_call;
86 start_time = ktime_get();
87 for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
88 if (nr != gup->nr_pages_per_call)
91 next = addr + nr * PAGE_SIZE;
92 if (next > gup->addr + gup->size) {
93 next = gup->addr + gup->size;
94 nr = (next - addr) / PAGE_SIZE;
97 /* Filter out most gup flags: only allow a tiny subset here: */
98 gup->flags &= FOLL_WRITE;
101 case GUP_FAST_BENCHMARK:
102 nr = get_user_pages_fast(addr, nr, gup->flags,
106 nr = get_user_pages(addr, nr, gup->flags, pages + i,
109 case PIN_FAST_BENCHMARK:
110 nr = pin_user_pages_fast(addr, nr, gup->flags,
114 nr = pin_user_pages(addr, nr, gup->flags, pages + i,
117 case PIN_LONGTERM_BENCHMARK:
118 nr = pin_user_pages(addr, nr,
119 gup->flags | FOLL_LONGTERM,
132 end_time = ktime_get();
134 /* Shifting the meaning of nr_pages: now it is actual number pinned: */
137 gup->get_delta_usec = ktime_us_delta(end_time, start_time);
138 gup->size = addr - gup->addr;
141 * Take an un-benchmark-timed moment to verify DMA pinned
142 * state: print a warning if any non-dma-pinned pages are found:
144 verify_dma_pinned(cmd, pages, nr_pages);
146 start_time = ktime_get();
148 put_back_pages(cmd, pages, nr_pages);
150 end_time = ktime_get();
151 gup->put_delta_usec = ktime_us_delta(end_time, start_time);
158 static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
161 struct gup_benchmark gup;
165 case GUP_FAST_BENCHMARK:
167 case PIN_FAST_BENCHMARK:
169 case PIN_LONGTERM_BENCHMARK:
175 if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
178 ret = __gup_benchmark_ioctl(cmd, &gup);
182 if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
188 static const struct file_operations gup_benchmark_fops = {
189 .open = nonseekable_open,
190 .unlocked_ioctl = gup_benchmark_ioctl,
193 static int gup_benchmark_init(void)
195 debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
196 &gup_benchmark_fops);
201 late_initcall(gup_benchmark_init);