summaryrefslogtreecommitdiffstats
path: root/tools/io_uring/io_uring-bench.c
blob: 7703f011838540e66061cd04bb0b1792304ded13 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
// SPDX-License-Identifier: GPL-2.0
/*
 * Simple benchmark program that uses the various features of io_uring
 * to provide fast random access to a device/file. It has various
 * options that are control how we use io_uring, see the OPTIONS section
 * below. This uses the raw io_uring interface.
 *
 * Copyright (C) 2018-2019 Jens Axboe
 */
#include <stdio.h>
#include <errno.h>
#include <assert.h>
#include <stdlib.h>
#include <stddef.h>
#include <signal.h>
#include <inttypes.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/syscall.h>
#include <sys/resource.h>
#include <sys/mman.h>
#include <sys/uio.h>
#include <linux/fs.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <pthread.h>
#include <sched.h>

#include "liburing.h"
#include "barrier.h"

#define min(a, b)		((a < b) ? (a) : (b))

struct io_sq_ring {
	unsigned *head;
	unsigned *tail;
	unsigned *ring_mask;
	unsigned *ring_entries;
	unsigned *flags;
	unsigned *array;
};

struct io_cq_ring {
	unsigned *head;
	unsigned *tail;
	unsigned *ring_mask;
	unsigned *ring_entries;
	struct io_uring_cqe *cqes;
};

#define DEPTH			128

#define BATCH_SUBMIT		32
#define BATCH_COMPLETE		32

#define BS			4096

#define MAX_FDS			16

static unsigned sq_ring_mask, cq_ring_mask;

struct file {
	unsigned long max_blocks;
	unsigned pending_ios;
	int real_fd;
	int fixed_fd;
};

struct submitter {
	pthread_t thread;
	int ring_fd;
	struct drand48_data rand;
	struct io_sq_ring sq_ring;
	struct io_uring_sqe *sqes;
	struct iovec iovecs[DEPTH];
	struct io_cq_ring cq_ring;
	int inflight;
	unsigned long reaps;
	unsigned long done;
	unsigned long calls;
	volatile int finish;

	__s32 *fds;

	struct file files[MAX_FDS];
	unsigned nr_files;
	unsigned cur_file;
};

static struct submitter submitters[1];
static volatile int finish;

/*
 * OPTIONS: Set these to test the various features of io_uring.
 */
static int polled = 1;		/* use IO polling */
static int fixedbufs = 1;	/* use fixed user buffers */
static int register_files = 1;	/* use fixed files */
static int buffered = 0;	/* use buffered IO, not O_DIRECT */
static int sq_thread_poll = 0;	/* use kernel submission/poller thread */
static int sq_thread_cpu = -1;	/* pin above thread to this CPU */
static int do_nop = 0;		/* no-op SQ ring commands */

static int io_uring_register_buffers(struct submitter *s)
{
	if (do_nop)
		return 0;

	return io_uring_register(s->ring_fd, IORING_REGISTER_BUFFERS, s->iovecs,
					DEPTH);
}

static int io_uring_register_files(struct submitter *s)
{
	unsigned i;

	if (do_nop)
		return 0;

	s->fds = calloc(s->nr_files, sizeof(__s32));
	for (i = 0; i < s->nr_files; i++) {
		s->fds[i] = s->files[i].real_fd;
		s->files[i].fixed_fd = i;
	}

	return io_uring_register(s->ring_fd, IORING_REGISTER_FILES, s->fds,
					s->nr_files);
}

static int lk_gettid(void)
{
	return syscall(__NR_gettid);
}

static unsigned file_depth(struct submitter *s)
{
	return (DEPTH + s->nr_files - 1) / s->nr_files;
}

static void init_io(struct submitter *s, unsigned index)
{
	struct io_uring_sqe *sqe = &s->sqes[index];
	unsigned long offset;
	struct file *f;
	long r;

	if (do_nop) {
		sqe->opcode = IORING_OP_NOP;
		return;
	}

	if (s->nr_files == 1) {
		f = &s->files[0];
	} else {
		f = &s->files[s->cur_file];
		if (f->pending_ios >= file_depth(s)) {
			s->cur_file++;
			if (s->cur_file == s->nr_files)
				s->cur_file = 0;
			f = &s->files[s->cur_file];
		}
	}
	f->pending_ios++;

	lrand48_r(&s->rand, &r);
	offset = (r % (f->max_blocks - 1)) * BS;

	if (register_files) {
		sqe->flags = IOSQE_FIXED_FILE;
		sqe->fd = f->fixed_fd;
	} else {
		sqe->flags = 0;
		sqe->fd = f->real_fd;
	}
	if (fixedbufs) {
		sqe->opcode = IORING_OP_READ_FIXED;
		sqe->addr = (unsigned long) s->iovecs[index].iov_base;
		sqe->len = BS;
		sqe->buf_index = index;
	} else {
		sqe->opcode = IORING_OP_READV;
		sqe->addr = (unsigned long) &s->iovecs[index];
		sqe->len = 1;
		sqe->buf_index = 0;
	}
	sqe->ioprio = 0;
	sqe->off = offset;
	sqe->user_data = (unsigned long) f;
}

static int prep_more_ios(struct submitter *s, unsigned max_ios)
{
	struct io_sq_ring *ring = &s->sq_ring;
	unsigned index, tail, next_tail, prepped = 0;

	next_tail = tail = *ring->tail;
	do {
		next_tail++;
		read_barrier();
		if (next_tail == *ring->head)
			break;

		index = tail & sq_ring_mask;
		init_io(s, index);
		ring->array[index] = index;
		prepped++;
		tail = next_tail;
	} while (prepped < max_ios);

	if (*ring->tail != tail) {
		/* order tail store with writes to sqes above */
		write_barrier();
		*ring->tail = tail;
		write_barrier();
	}
	return prepped;
}

static int get_file_size(struct file *f)
{
	struct stat st;

	if (fstat(f->real_fd, &st) < 0)
		return -1;
	if (S_ISBLK(st.st_mode)) {
		unsigned long long bytes;

		if (ioctl(f->real_fd, BLKGETSIZE64, &bytes) != 0)
			return -1;

		f->max_blocks = bytes / BS;
		return 0;
	} else if (S_ISREG(st.st_mode)) {
		f->max_blocks = st.st_size / BS;
		return 0;
	}

	return -1;
}

static int reap_events(struct submitter *s)
{
	struct io_cq_ring *ring = &s->cq_ring;
	struct io_uring_cqe *cqe;
	unsigned head, reaped = 0;

	head = *ring->head;
	do {
		struct file *f;

		read_barrier();
		if (head == *ring->tail)
			break;
		cqe = &ring->cqes[head & cq_ring_mask];
		if (!do_nop) {
			f = (struct file *) (uintptr_t) cqe->user_data;
			f->pending_ios--;
			if (cqe->res != BS) {
				printf("io: unexpected ret=%d\n", cqe->res);
				if (polled && cqe->res == -EOPNOTSUPP)
					printf("Your filesystem doesn't support poll\n");
				return -1;
			}
		}
		reaped++;
		head++;
	} while (1);

	s->inflight -= reaped;
	*ring->head = head;
	write_barrier();
	return reaped;
}

static void *submitter_fn(void *data)
{
	struct submitter *s = data;
	struct io_sq_ring *ring = &s->sq_ring;
	int ret, prepped;

	printf("submitter=%d\n", lk_gettid());

	srand48_r(pthread_self(), &s->rand);

	prepped = 0;
	do {
		int to_wait, to_submit, this_reap, to_prep;

		if (!prepped && s->inflight < DEPTH) {
			to_prep = min(DEPTH - s->inflight, BATCH_SUBMIT);
			prepped = prep_more_ios(s, to_prep);
		}
		s->inflight += prepped;
submit_more:
		to_submit = prepped;
submit:
		if (to_submit && (s->inflight + to_submit <= DEPTH))
			to_wait = 0;
		else
			to_wait = min(s->inflight + to_submit, BATCH_COMPLETE);

		/*
		 * Only need to call io_uring_enter if we're not using SQ thread
		 * poll, or if IORING_SQ_NEED_WAKEUP is set.
		 */
		if (!sq_thread_poll || (*ring->flags & IORING_SQ_NEED_WAKEUP)) {
			unsigned flags = 0;

			if (to_wait)
				flags = IORING_ENTER_GETEVENTS;
			if ((*ring->flags & IORING_SQ_NEED_WAKEUP))
				flags |= IORING_ENTER_SQ_WAKEUP;
			ret = io_uring_enter(s->ring_fd, to_submit, to_wait,
						flags, NULL);
			s->calls++;
		}

		/*
		 * For non SQ thread poll, we already got the events we needed
		 * through the io_uring_enter() above. For SQ thread poll, we
		 * need to loop here until we find enough events.
		 */
		this_reap = 0;
		do {
			int r;
			r = reap_events(s);
			if (r == -1) {
				s->finish = 1;
				break;
			} else if (r > 0)
				this_reap += r;
		} while (sq_thread_poll && this_reap < to_wait);
		s->reaps += this_reap;

		if (ret >= 0) {
			if (!ret) {
				to_submit = 0;
				if (s->inflight)
					goto submit;
				continue;
			} else if (ret < to_submit) {
				int diff = to_submit - ret;

				s->done += ret;
				prepped -= diff;
				goto submit_more;
			}
			s->done += ret;
			prepped = 0;
			continue;
		} else if (ret < 0) {
			if (errno == EAGAIN) {
				if (s->finish)
					break;
				if (this_reap)
					goto submit;
				to_submit = 0;
				goto submit;
			}
			printf("io_submit: %s\n", strerror(errno));
			break;
		}
	} while (!s->finish);

	finish = 1;
	return NULL;
}

static void sig_int(int sig)
{
	printf("Exiting on signal %d\n", sig);
	submitters[0].finish = 1;
	finish = 1;
}

static void arm_sig_int(void)
{
	struct sigaction act;

	memset(&act, 0, sizeof(act));
	act.sa_handler = sig_int;
	act.sa_flags = SA_RESTART;
	sigaction(SIGINT, &act, NULL);
}

static int setup_ring(struct submitter *s)
{
	struct io_sq_ring *sring = &s->sq_ring;
	struct io_cq_ring *cring = &s->cq_ring;
	struct io_uring_params p;
	int ret, fd;
	void *ptr;

	memset(&p, 0, sizeof(p));

	if (polled && !do_nop)
		p.flags |= IORING_SETUP_IOPOLL;
	if (sq_thread_poll) {
		p.flags |= IORING_SETUP_SQPOLL;
		if (sq_thread_cpu != -1) {
			p.flags |= IORING_SETUP_SQ_AFF;
			p.sq_thread_cpu = sq_thread_cpu;
		}
	}

	fd = io_uring_setup(DEPTH, &p);
	if (fd < 0) {
		perror("io_uring_setup");
		return 1;
	}
	s->ring_fd = fd;

	if (fixedbufs) {
		ret = io_uring_register_buffers(s);
		if (ret < 0) {
			perror("io_uring_register_buffers");
			return 1;
		}
	}

	if (register_files) {
		ret = io_uring_register_files(s);
		if (ret < 0) {
			perror("io_uring_register_files");
			return 1;
		}
	}

	ptr = mmap(0, p.sq_off.array + p.sq_entries * sizeof(__u32),
			PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd,
			IORING_OFF_SQ_RING);
	printf("sq_ring ptr = 0x%p\n", ptr);
	sring->head = ptr + p.sq_off.head;
	sring->tail = ptr + p.sq_off.tail;
	sring->ring_mask = ptr + p.sq_off.ring_mask;
	sring->ring_entries = ptr + p.sq_off.ring_entries;
	sring->flags = ptr + p.sq_off.flags;
	sring->array = ptr + p.sq_off.array;
	sq_ring_mask = *sring->ring_mask;

	s->sqes = mmap(0, p.sq_entries * sizeof(struct io_uring_sqe),
			PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd,
			IORING_OFF_SQES);
	printf("sqes ptr    = 0x%p\n", s->sqes);

	ptr = mmap(0, p.cq_off.cqes + p.cq_entries * sizeof(struct io_uring_cqe),
			PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd,
			IORING_OFF_CQ_RING);
	printf("cq_ring ptr = 0x%p\n", ptr);
	cring->head = ptr + p.cq_off.head;
	cring->tail = ptr + p.cq_off.tail;
	cring->ring_mask = ptr + p.cq_off.ring_mask;
	cring->ring_entries = ptr + p.cq_off.ring_entries;
	cring->cqes = ptr + p.cq_off.cqes;
	cq_ring_mask = *cring->ring_mask;
	return 0;
}

static void file_depths(char *buf)
{
	struct submitter *s = &submitters[0];
	unsigned i;
	char *p;

	buf[0] = '\0';
	p = buf;
	for (i = 0; i < s->nr_files; i++) {
		struct file *f = &s->files[i];

		if (i + 1 == s->nr_files)
			p += sprintf(p, "%d", f->pending_ios);
		else
			p += sprintf(p, "%d, ", f->pending_ios);
	}
}

int main(int argc, char *argv[])
{
	struct submitter *s = &submitters[0];
	unsigned long done, calls, reap;
	int err, i, flags, fd;
	char *fdepths;
	void *ret;

	if (!do_nop && argc < 2) {
		printf("%s: filename\n", argv[0]);
		return 1;
	}

	flags = O_RDONLY | O_NOATIME;
	if (!buffered)
		flags |= O_DIRECT;

	i = 1;
	while (!do_nop && i < argc) {
		struct file *f;

		if (s->nr_files == MAX_FDS) {
			printf("Max number of files (%d) reached\n", MAX_FDS);
			break;
		}
		fd = open(argv[i], flags);
		if (fd < 0) {
			perror("open");
			return 1;
		}

		f = &s->files[s->nr_files];
		f->real_fd = fd;
		if (get_file_size(f)) {
			printf("failed getting size of device/file\n");
			return 1;
		}
		if (f->max_blocks <= 1) {
			printf("Zero file/device size?\n");
			return 1;
		}
		f->max_blocks--;

		printf("Added file %s\n", argv[i]);
		s->nr_files++;
		i++;
	}

	if (fixedbufs) {
		struct rlimit rlim;

		rlim.rlim_cur = RLIM_INFINITY;
		rlim.rlim_max = RLIM_INFINITY;
		if (setrlimit(RLIMIT_MEMLOCK, &rlim) < 0) {
			perror("setrlimit");
			return 1;
		}
	}

	arm_sig_int();

	for (i = 0; i < DEPTH; i++) {
		void *buf;

		if (posix_memalign(&buf, BS, BS)) {
			printf("failed alloc\n");
			return 1;
		}
		s->iovecs[i].iov_base = buf;
		s->iovecs[i].iov_len = BS;
	}

	err = setup_ring(s);
	if (err) {
		printf("ring setup failed: %s, %d\n", strerror(errno), err);
		return 1;
	}
	printf("polled=%d, fixedbufs=%d, buffered=%d", polled, fixedbufs, buffered);
	printf(" QD=%d, sq_ring=%d, cq_ring=%d\n", DEPTH, *s->sq_ring.ring_entries, *s->cq_ring.ring_entries);

	pthread_create(&s->thread, NULL, submitter_fn, s);

	fdepths = malloc(8 * s->nr_files);
	reap = calls = done = 0;
	do {
		unsigned long this_done = 0;
		unsigned long this_reap = 0;
		unsigned long this_call = 0;
		unsigned long rpc = 0, ipc = 0;

		sleep(1);
		this_done += s->done;
		this_call += s->calls;
		this_reap += s->reaps;
		if (this_call - calls) {
			rpc = (this_done - done) / (this_call - calls);
			ipc = (this_reap - reap) / (this_call - calls);
		} else
			rpc = ipc = -1;
		file_depths(fdepths);
		printf("IOPS=%lu, IOS/call=%ld/%ld, inflight=%u (%s)\n",
				this_done - done, rpc, ipc, s->inflight,
				fdepths);
		done = this_done;
		calls = this_call;
		reap = this_reap;
	} while (!finish);

	pthread_join(s->thread, &ret);
	close(s->ring_fd);
	free(fdepths);
	return 0;
}