[linux-2.6-block.git] / mm / gup_benchmark.c

#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_LONGTERM_BENCHMARK	_IOWR('g', 2, struct gup_benchmark)
#define GUP_BENCHMARK		_IOWR('g', 3, 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 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;

	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;

	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;
		}

		switch (cmd) {
		case GUP_FAST_BENCHMARK:
			nr = get_user_pages_fast(addr, nr, gup->flags & 1,
						 pages + i);
			break;
		case GUP_LONGTERM_BENCHMARK:
			nr = get_user_pages(addr, nr,
					    (gup->flags & 1) | FOLL_LONGTERM,
					    pages + i, NULL);
			break;
		case GUP_BENCHMARK:
			nr = get_user_pages(addr, nr, gup->flags & 1, pages + i,
					    NULL);
			break;
		default:
			return -1;
		}

		if (nr <= 0)
			break;
		i += nr;
	}
	end_time = ktime_get();

	gup->get_delta_usec = ktime_us_delta(end_time, start_time);
	gup->size = addr - gup->addr;

	start_time = ktime_get();
	for (i = 0; i < nr_pages; i++) {
		if (!pages[i])
			break;
		put_page(pages[i]);
	}
	end_time = ktime_get();
	gup->put_delta_usec = ktime_us_delta(end_time, start_time);

	kvfree(pages);
	return 0;
}

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_LONGTERM_BENCHMARK:
	case GUP_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);
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)
714a3a1e KB	9	#define GUP_LONGTERM_BENCHMARK _IOWR('g', 2, struct gup_benchmark)
714a3a1e KB	10	#define GUP_BENCHMARK _IOWR('g', 3, struct gup_benchmark)
64c349f4 KS	11
64c349f4 KS	12	struct gup_benchmark {
26db3d09 KB	13	__u64 get_delta_usec;
26db3d09 KB	14	__u64 put_delta_usec;
64c349f4 KS	15	__u64 addr;
	16	__u64 size;
	17	__u32 nr_pages_per_call;
	18	__u32 flags;
26db3d09	19	__u64 expansion[10]; /* For future use */
64c349f4 KS	20	};
	21
	22	static int __gup_benchmark_ioctl(unsigned int cmd,
	23	struct gup_benchmark *gup)
	24	{
	25	ktime_t start_time, end_time;
51896864 Y	26	unsigned long i, nr_pages, addr, next;
51896864 Y	27	int nr;
64c349f4 KS	28	struct page **pages;
64c349f4 KS	29
4b408c74 DC	30	if (gup->size > ULONG_MAX)
	31	return -EINVAL;
	32
64c349f4	33	nr_pages = gup->size / PAGE_SIZE;
778e1cdd	34	pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
64c349f4 KS	35	if (!pages)
	36	return -ENOMEM;
	37
	38	i = 0;
	39	nr = gup->nr_pages_per_call;
	40	start_time = ktime_get();
	41	for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
	42	if (nr != gup->nr_pages_per_call)
	43	break;
	44
	45	next = addr + nr * PAGE_SIZE;
	46	if (next > gup->addr + gup->size) {
	47	next = gup->addr + gup->size;
	48	nr = (next - addr) / PAGE_SIZE;
	49	}
	50
714a3a1e KB	51	switch (cmd) {
	52	case GUP_FAST_BENCHMARK:
	53	nr = get_user_pages_fast(addr, nr, gup->flags & 1,
	54	pages + i);
	55	break;
	56	case GUP_LONGTERM_BENCHMARK:
932f4a63 IW	57	nr = get_user_pages(addr, nr,
	58	(gup->flags & 1) \| FOLL_LONGTERM,
	59	pages + i, NULL);
714a3a1e KB	60	break;
	61	case GUP_BENCHMARK:
	62	nr = get_user_pages(addr, nr, gup->flags & 1, pages + i,
	63	NULL);
	64	break;
	65	default:
	66	return -1;
	67	}
	68
09e35a4a MT	69	if (nr <= 0)
09e35a4a MT	70	break;
64c349f4 KS	71	i += nr;
	72	}
	73	end_time = ktime_get();
	74
26db3d09	75	gup->get_delta_usec = ktime_us_delta(end_time, start_time);
64c349f4 KS	76	gup->size = addr - gup->addr;
64c349f4 KS	77
26db3d09	78	start_time = ktime_get();
64c349f4 KS	79	for (i = 0; i < nr_pages; i++) {
	80	if (!pages[i])
	81	break;
	82	put_page(pages[i]);
	83	}
26db3d09 KB	84	end_time = ktime_get();
26db3d09 KB	85	gup->put_delta_usec = ktime_us_delta(end_time, start_time);
64c349f4 KS	86
	87	kvfree(pages);
	88	return 0;
	89	}
	90
	91	static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
	92	unsigned long arg)
	93	{
	94	struct gup_benchmark gup;
	95	int ret;
	96
714a3a1e KB	97	switch (cmd) {
	98	case GUP_FAST_BENCHMARK:
	99	case GUP_LONGTERM_BENCHMARK:
	100	case GUP_BENCHMARK:
	101	break;
	102	default:
64c349f4	103	return -EINVAL;
714a3a1e	104	}
64c349f4 KS	105
	106	if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
	107	return -EFAULT;
	108
	109	ret = __gup_benchmark_ioctl(cmd, &gup);
	110	if (ret)
	111	return ret;
	112
	113	if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
	114	return -EFAULT;
	115
	116	return 0;
	117	}
	118
	119	static const struct file_operations gup_benchmark_fops = {
	120	.open = nonseekable_open,
	121	.unlocked_ioctl = gup_benchmark_ioctl,
	122	};
	123
	124	static int gup_benchmark_init(void)
	125	{
d9f7979c GKH	126	debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
d9f7979c GKH	127	&gup_benchmark_fops);
64c349f4 KS	128
	129	return 0;
	130	}
	131
	132	late_initcall(gup_benchmark_init);