[thirdparty/linux.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)
#define PIN_FAST_BENCHMARK	_IOWR('g', 4, struct gup_benchmark)
#define PIN_BENCHMARK		_IOWR('g', 5, 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 void put_back_pages(unsigned int cmd, struct page **pages,
			   unsigned long nr_pages)
{
	unsigned long i;

	switch (cmd) {
	case GUP_FAST_BENCHMARK:
	case GUP_LONGTERM_BENCHMARK:
	case GUP_BENCHMARK:
		for (i = 0; i < nr_pages; i++)
			put_page(pages[i]);
		break;

	case PIN_FAST_BENCHMARK:
	case PIN_BENCHMARK:
		unpin_user_pages(pages, nr_pages);
		break;
	}
}

static void verify_dma_pinned(unsigned int cmd, struct page **pages,
			      unsigned long nr_pages)
{
	unsigned long i;
	struct page *page;

	switch (cmd) {
	case PIN_FAST_BENCHMARK:
	case PIN_BENCHMARK:
		for (i = 0; i < nr_pages; i++) {
			page = pages[i];
			if (WARN(!page_maybe_dma_pinned(page),
				 "pages[%lu] is NOT dma-pinned\n", i)) {

				dump_page(page, "gup_benchmark failure");
				break;
			}
		}
		break;
	}
}

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;
		case PIN_FAST_BENCHMARK:
			nr = pin_user_pages_fast(addr, nr, gup->flags,
						 pages + i);
			break;
		case PIN_BENCHMARK:
			nr = pin_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();

	/* Shifting the meaning of nr_pages: now it is actual number pinned: */
	nr_pages = i;

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

	/*
	 * Take an un-benchmark-timed moment to verify DMA pinned
	 * state: print a warning if any non-dma-pinned pages are found:
	 */
	verify_dma_pinned(cmd, pages, nr_pages);

	start_time = ktime_get();

	put_back_pages(cmd, pages, nr_pages);

	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:
	case PIN_FAST_BENCHMARK:
	case PIN_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)
41c45d37 JH	11	#define PIN_FAST_BENCHMARK _IOWR('g', 4, struct gup_benchmark)
41c45d37 JH	12	#define PIN_BENCHMARK _IOWR('g', 5, struct gup_benchmark)
64c349f4 KS	13
64c349f4 KS	14	struct gup_benchmark {
26db3d09 KB	15	__u64 get_delta_usec;
26db3d09 KB	16	__u64 put_delta_usec;
64c349f4 KS	17	__u64 addr;
	18	__u64 size;
	19	__u32 nr_pages_per_call;
	20	__u32 flags;
26db3d09	21	__u64 expansion[10]; /* For future use */
64c349f4 KS	22	};
64c349f4 KS	23
41c45d37 JH	24	static void put_back_pages(unsigned int cmd, struct page **pages,
	25	unsigned long nr_pages)
	26	{
	27	unsigned long i;
	28
	29	switch (cmd) {
	30	case GUP_FAST_BENCHMARK:
	31	case GUP_LONGTERM_BENCHMARK:
	32	case GUP_BENCHMARK:
	33	for (i = 0; i < nr_pages; i++)
	34	put_page(pages[i]);
	35	break;
	36
	37	case PIN_FAST_BENCHMARK:
	38	case PIN_BENCHMARK:
	39	unpin_user_pages(pages, nr_pages);
	40	break;
	41	}
	42	}
	43
	44	static void verify_dma_pinned(unsigned int cmd, struct page **pages,
	45	unsigned long nr_pages)
	46	{
	47	unsigned long i;
	48	struct page *page;
	49
	50	switch (cmd) {
	51	case PIN_FAST_BENCHMARK:
	52	case PIN_BENCHMARK:
	53	for (i = 0; i < nr_pages; i++) {
	54	page = pages[i];
	55	if (WARN(!page_maybe_dma_pinned(page),
	56	"pages[%lu] is NOT dma-pinned\n", i)) {
	57
	58	dump_page(page, "gup_benchmark failure");
	59	break;
	60	}
	61	}
	62	break;
	63	}
	64	}
	65
64c349f4 KS	66	static int __gup_benchmark_ioctl(unsigned int cmd,
	67	struct gup_benchmark *gup)
	68	{
	69	ktime_t start_time, end_time;
51896864 Y	70	unsigned long i, nr_pages, addr, next;
51896864 Y	71	int nr;
64c349f4	72	struct page **pages;
a7c46c0c	73	int ret = 0;
64c349f4	74
4b408c74 DC	75	if (gup->size > ULONG_MAX)
	76	return -EINVAL;
	77
64c349f4	78	nr_pages = gup->size / PAGE_SIZE;
778e1cdd	79	pages = kvcalloc(nr_pages, sizeof(void *), GFP_KERNEL);
64c349f4 KS	80	if (!pages)
	81	return -ENOMEM;
	82
	83	i = 0;
	84	nr = gup->nr_pages_per_call;
	85	start_time = ktime_get();
	86	for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
	87	if (nr != gup->nr_pages_per_call)
	88	break;
	89
	90	next = addr + nr * PAGE_SIZE;
	91	if (next > gup->addr + gup->size) {
	92	next = gup->addr + gup->size;
	93	nr = (next - addr) / PAGE_SIZE;
	94	}
	95
bdffe23e JH	96	/* Filter out most gup flags: only allow a tiny subset here: */
	97	gup->flags &= FOLL_WRITE;
	98
714a3a1e KB	99	switch (cmd) {
714a3a1e KB	100	case GUP_FAST_BENCHMARK:
bdffe23e	101	nr = get_user_pages_fast(addr, nr, gup->flags,
714a3a1e KB	102	pages + i);
	103	break;
	104	case GUP_LONGTERM_BENCHMARK:
932f4a63	105	nr = get_user_pages(addr, nr,
bdffe23e	106	gup->flags \| FOLL_LONGTERM,
932f4a63	107	pages + i, NULL);
714a3a1e KB	108	break;
714a3a1e KB	109	case GUP_BENCHMARK:
bdffe23e	110	nr = get_user_pages(addr, nr, gup->flags, pages + i,
714a3a1e KB	111	NULL);
714a3a1e KB	112	break;
41c45d37 JH	113	case PIN_FAST_BENCHMARK:
	114	nr = pin_user_pages_fast(addr, nr, gup->flags,
	115	pages + i);
	116	break;
	117	case PIN_BENCHMARK:
	118	nr = pin_user_pages(addr, nr, gup->flags, pages + i,
	119	NULL);
	120	break;
714a3a1e	121	default:
a7c46c0c NE	122	kvfree(pages);
	123	ret = -EINVAL;
	124	goto out;
714a3a1e KB	125	}
714a3a1e KB	126
09e35a4a MT	127	if (nr <= 0)
09e35a4a MT	128	break;
64c349f4 KS	129	i += nr;
	130	}
	131	end_time = ktime_get();
	132
41c45d37 JH	133	/* Shifting the meaning of nr_pages: now it is actual number pinned: */
	134	nr_pages = i;
	135
26db3d09	136	gup->get_delta_usec = ktime_us_delta(end_time, start_time);
64c349f4 KS	137	gup->size = addr - gup->addr;
64c349f4 KS	138
41c45d37 JH	139	/*
	140	* Take an un-benchmark-timed moment to verify DMA pinned
	141	* state: print a warning if any non-dma-pinned pages are found:
	142	*/
	143	verify_dma_pinned(cmd, pages, nr_pages);
	144
26db3d09	145	start_time = ktime_get();
41c45d37 JH	146
	147	put_back_pages(cmd, pages, nr_pages);
	148
26db3d09 KB	149	end_time = ktime_get();
26db3d09 KB	150	gup->put_delta_usec = ktime_us_delta(end_time, start_time);
64c349f4 KS	151
64c349f4 KS	152	kvfree(pages);
a7c46c0c NE	153	out:
a7c46c0c NE	154	return ret;
64c349f4 KS	155	}
	156
	157	static long gup_benchmark_ioctl(struct file *filep, unsigned int cmd,
	158	unsigned long arg)
	159	{
	160	struct gup_benchmark gup;
	161	int ret;
	162
714a3a1e KB	163	switch (cmd) {
	164	case GUP_FAST_BENCHMARK:
	165	case GUP_LONGTERM_BENCHMARK:
	166	case GUP_BENCHMARK:
41c45d37 JH	167	case PIN_FAST_BENCHMARK:
41c45d37 JH	168	case PIN_BENCHMARK:
714a3a1e KB	169	break;
714a3a1e KB	170	default:
64c349f4	171	return -EINVAL;
714a3a1e	172	}
64c349f4 KS	173
	174	if (copy_from_user(&gup, (void __user *)arg, sizeof(gup)))
	175	return -EFAULT;
	176
	177	ret = __gup_benchmark_ioctl(cmd, &gup);
	178	if (ret)
	179	return ret;
	180
	181	if (copy_to_user((void __user *)arg, &gup, sizeof(gup)))
	182	return -EFAULT;
	183
	184	return 0;
	185	}
	186
	187	static const struct file_operations gup_benchmark_fops = {
	188	.open = nonseekable_open,
	189	.unlocked_ioctl = gup_benchmark_ioctl,
	190	};
	191
	192	static int gup_benchmark_init(void)
	193	{
d9f7979c GKH	194	debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
d9f7979c GKH	195	&gup_benchmark_fops);
64c349f4 KS	196
	197	return 0;
	198	}
	199
	200	late_initcall(gup_benchmark_init);