[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)

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;

	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;
		}

		nr = get_user_pages_fast(addr, nr, gup->flags & 1, pages + i);
		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;

	if (cmd != GUP_FAST_BENCHMARK)
		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)
{
	void *ret;

	ret = debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
			&gup_benchmark_fops);
	if (!ret)
		pr_warn("Failed to create gup_benchmark in debugfs");

	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)
	9
	10	struct gup_benchmark {
26db3d09 KB	11	__u64 get_delta_usec;
26db3d09 KB	12	__u64 put_delta_usec;
64c349f4 KS	13	__u64 addr;
	14	__u64 size;
	15	__u32 nr_pages_per_call;
	16	__u32 flags;
26db3d09	17	__u64 expansion[10]; /* For future use */
64c349f4 KS	18	};
	19
	20	static int __gup_benchmark_ioctl(unsigned int cmd,
	21	struct gup_benchmark *gup)
	22	{
	23	ktime_t start_time, end_time;
51896864 Y	24	unsigned long i, nr_pages, addr, next;
51896864 Y	25	int nr;
64c349f4 KS	26	struct page **pages;
	27
	28	nr_pages = gup->size / PAGE_SIZE;
778e1cdd	29	pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
64c349f4 KS	30	if (!pages)
	31	return -ENOMEM;
	32
	33	i = 0;
	34	nr = gup->nr_pages_per_call;
	35	start_time = ktime_get();
	36	for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
	37	if (nr != gup->nr_pages_per_call)
	38	break;
	39
	40	next = addr + nr * PAGE_SIZE;
	41	if (next > gup->addr + gup->size) {
	42	next = gup->addr + gup->size;
	43	nr = (next - addr) / PAGE_SIZE;
	44	}
	45
	46	nr = get_user_pages_fast(addr, nr, gup->flags & 1, pages + i);
09e35a4a MT	47	if (nr <= 0)
09e35a4a MT	48	break;
64c349f4 KS	49	i += nr;
	50	}
	51	end_time = ktime_get();
	52
26db3d09	53	gup->get_delta_usec = ktime_us_delta(end_time, start_time);
64c349f4 KS	54	gup->size = addr - gup->addr;
64c349f4 KS	55
26db3d09	56	start_time = ktime_get();
64c349f4 KS	57	for (i = 0; i < nr_pages; i++) {
	58	if (!pages[i])
	59	break;
	60	put_page(pages[i]);
	61	}
26db3d09 KB	62	end_time = ktime_get();
26db3d09 KB	63	gup->put_delta_usec = ktime_us_delta(end_time, start_time);
64c349f4 KS	64
	65	kvfree(pages);
	66	return 0;
	67	}
	68
	69	static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
	70	unsigned long arg)
	71	{
	72	struct gup_benchmark gup;
	73	int ret;
	74
	75	if (cmd != GUP_FAST_BENCHMARK)
	76	return -EINVAL;
	77
	78	if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
	79	return -EFAULT;
	80
	81	ret = __gup_benchmark_ioctl(cmd, &gup);
	82	if (ret)
	83	return ret;
	84
	85	if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
	86	return -EFAULT;
	87
	88	return 0;
	89	}
	90
	91	static const struct file_operations gup_benchmark_fops = {
	92	.open = nonseekable_open,
	93	.unlocked_ioctl = gup_benchmark_ioctl,
	94	};
	95
	96	static int gup_benchmark_init(void)
	97	{
	98	void *ret;
	99
	100	ret = debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
	101	&gup_benchmark_fops);
	102	if (!ret)
	103	pr_warn("Failed to create gup_benchmark in debugfs");
	104
	105	return 0;
	106	}
	107
	108	late_initcall(gup_benchmark_init);