[mirror_ubuntu-bionic-kernel.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 delta_usec;
	__u64 addr;
	__u64 size;
	__u32 nr_pages_per_call;
	__u32 flags;
};

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 = kvzalloc(sizeof(void *) * nr_pages, 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->delta_usec = ktime_us_delta(end_time, start_time);
	gup->size = addr - gup->addr;

	for (i = 0; i < nr_pages; i++) {
		if (!pages[i])
			break;
		put_page(pages[i]);
	}

	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 {
	11	__u64 delta_usec;
	12	__u64 addr;
	13	__u64 size;
	14	__u32 nr_pages_per_call;
	15	__u32 flags;
	16	};
	17
	18	static int __gup_benchmark_ioctl(unsigned int cmd,
	19	struct gup_benchmark *gup)
	20	{
	21	ktime_t start_time, end_time;
5ca90cd1 Y	22	unsigned long i, nr_pages, addr, next;
5ca90cd1 Y	23	int nr;
64c349f4 KS	24	struct page **pages;
64c349f4 KS	25
15e01792 DC	26	if (gup->size > ULONG_MAX)
	27	return -EINVAL;
	28
64c349f4	29	nr_pages = gup->size / PAGE_SIZE;
cca4fdb1	30	pages = kvzalloc(sizeof(void ) nr_pages, GFP_KERNEL);
64c349f4 KS	31	if (!pages)
	32	return -ENOMEM;
	33
	34	i = 0;
	35	nr = gup->nr_pages_per_call;
	36	start_time = ktime_get();
	37	for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
	38	if (nr != gup->nr_pages_per_call)
	39	break;
	40
	41	next = addr + nr * PAGE_SIZE;
	42	if (next > gup->addr + gup->size) {
	43	next = gup->addr + gup->size;
	44	nr = (next - addr) / PAGE_SIZE;
	45	}
	46
	47	nr = get_user_pages_fast(addr, nr, gup->flags & 1, pages + i);
cca4fdb1 MT	48	if (nr <= 0)
cca4fdb1 MT	49	break;
64c349f4 KS	50	i += nr;
	51	}
	52	end_time = ktime_get();
	53
	54	gup->delta_usec = ktime_us_delta(end_time, start_time);
	55	gup->size = addr - gup->addr;
	56
	57	for (i = 0; i < nr_pages; i++) {
	58	if (!pages[i])
	59	break;
	60	put_page(pages[i]);
	61	}
	62
	63	kvfree(pages);
	64	return 0;
	65	}
	66
	67	static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
	68	unsigned long arg)
	69	{
	70	struct gup_benchmark gup;
	71	int ret;
	72
	73	if (cmd != GUP_FAST_BENCHMARK)
	74	return -EINVAL;
	75
	76	if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
	77	return -EFAULT;
	78
	79	ret = __gup_benchmark_ioctl(cmd, &gup);
	80	if (ret)
	81	return ret;
	82
	83	if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
	84	return -EFAULT;
	85
	86	return 0;
	87	}
	88
	89	static const struct file_operations gup_benchmark_fops = {
	90	.open = nonseekable_open,
	91	.unlocked_ioctl = gup_benchmark_ioctl,
	92	};
	93
	94	static int gup_benchmark_init(void)
	95	{
	96	void *ret;
	97
	98	ret = debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
	99	&gup_benchmark_fops);
	100	if (!ret)
	101	pr_warn("Failed to create gup_benchmark in debugfs");
	102
	103	return 0;
	104	}
	105
	106	late_initcall(gup_benchmark_init);