[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;
	int ret = 0;

	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;
		}

		/* 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_LONGTERM_BENCHMARK:
			nr = get_user_pages(addr, nr,
					    gup->flags | FOLL_LONGTERM,
					    pages + i, NULL);
			break;
		case GUP_BENCHMARK:
			nr = get_user_pages(addr, nr, gup->flags, pages + i,
					    NULL);
			break;
		default:
			kvfree(pages);
			ret = -EINVAL;
			goto out;
		}

		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);
out:
	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_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	28	struct page **pages;
a7c46c0c	29	int ret = 0;
64c349f4	30
4b408c74 DC	31	if (gup->size > ULONG_MAX)
	32	return -EINVAL;
	33
64c349f4	34	nr_pages = gup->size / PAGE_SIZE;
778e1cdd	35	pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
64c349f4 KS	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
bdffe23e JH	52	/* Filter out most gup flags: only allow a tiny subset here: */
	53	gup->flags &= FOLL_WRITE;
	54
714a3a1e KB	55	switch (cmd) {
714a3a1e KB	56	case GUP_FAST_BENCHMARK:
bdffe23e	57	nr = get_user_pages_fast(addr, nr, gup->flags,
714a3a1e KB	58	pages + i);
	59	break;
	60	case GUP_LONGTERM_BENCHMARK:
932f4a63	61	nr = get_user_pages(addr, nr,
bdffe23e	62	gup->flags \| FOLL_LONGTERM,
932f4a63	63	pages + i, NULL);
714a3a1e KB	64	break;
714a3a1e KB	65	case GUP_BENCHMARK:
bdffe23e	66	nr = get_user_pages(addr, nr, gup->flags, pages + i,
714a3a1e KB	67	NULL);
	68	break;
	69	default:
a7c46c0c NE	70	kvfree(pages);
	71	ret = -EINVAL;
	72	goto out;
714a3a1e KB	73	}
714a3a1e KB	74
09e35a4a MT	75	if (nr <= 0)
09e35a4a MT	76	break;
64c349f4 KS	77	i += nr;
	78	}
	79	end_time = ktime_get();
	80
26db3d09	81	gup->get_delta_usec = ktime_us_delta(end_time, start_time);
64c349f4 KS	82	gup->size = addr - gup->addr;
64c349f4 KS	83
26db3d09	84	start_time = ktime_get();
64c349f4 KS	85	for (i = 0; i < nr_pages; i++) {
	86	if (!pages[i])
	87	break;
	88	put_page(pages[i]);
	89	}
26db3d09 KB	90	end_time = ktime_get();
26db3d09 KB	91	gup->put_delta_usec = ktime_us_delta(end_time, start_time);
64c349f4 KS	92
64c349f4 KS	93	kvfree(pages);
a7c46c0c NE	94	out:
a7c46c0c NE	95	return ret;
64c349f4 KS	96	}
	97
	98	static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
	99	unsigned long arg)
	100	{
	101	struct gup_benchmark gup;
	102	int ret;
	103
714a3a1e KB	104	switch (cmd) {
	105	case GUP_FAST_BENCHMARK:
	106	case GUP_LONGTERM_BENCHMARK:
	107	case GUP_BENCHMARK:
	108	break;
	109	default:
64c349f4	110	return -EINVAL;
714a3a1e	111	}
64c349f4 KS	112
	113	if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
	114	return -EFAULT;
	115
	116	ret = __gup_benchmark_ioctl(cmd, &gup);
	117	if (ret)
	118	return ret;
	119
	120	if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
	121	return -EFAULT;
	122
	123	return 0;
	124	}
	125
	126	static const struct file_operations gup_benchmark_fops = {
	127	.open = nonseekable_open,
	128	.unlocked_ioctl = gup_benchmark_ioctl,
	129	};
	130
	131	static int gup_benchmark_init(void)
	132	{
d9f7979c GKH	133	debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
d9f7979c GKH	134	&gup_benchmark_fops);
64c349f4 KS	135
	136	return 0;
	137	}
	138
	139	late_initcall(gup_benchmark_init);