1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Simple benchmark program that uses the various features of io_uring
4 * to provide fast random access to a device/file. It has various
5 * options that are control how we use io_uring, see the OPTIONS section
6 * below. This uses the raw io_uring interface.
7 *
8 * Copyright (C) 2018-2019 Jens Axboe
9 */
10 #include <stdio.h>
11 #include <errno.h>
12 #include <assert.h>
13 #include <stdlib.h>
14 #include <stddef.h>
15 #include <signal.h>
16 #include <inttypes.h>
17
18 #include <sys/types.h>
19 #include <sys/stat.h>
20 #include <sys/ioctl.h>
21 #include <sys/syscall.h>
22 #include <sys/resource.h>
23 #include <sys/mman.h>
24 #include <sys/uio.h>
25 #include <linux/fs.h>
26 #include <fcntl.h>
27 #include <unistd.h>
28 #include <string.h>
29 #include <pthread.h>
30 #include <sched.h>
31
32 #include "liburing.h"
33 #include "barrier.h"
34
35 #define min(a, b) ((a < b) ? (a) : (b))
36
37 struct io_sq_ring {
38 unsigned *head;
39 unsigned *tail;
40 unsigned *ring_mask;
41 unsigned *ring_entries;
42 unsigned *flags;
43 unsigned *array;
44 };
45
46 struct io_cq_ring {
47 unsigned *head;
48 unsigned *tail;
49 unsigned *ring_mask;
50 unsigned *ring_entries;
51 struct io_uring_cqe *cqes;
52 };
53
54 #define DEPTH 128
55
56 #define BATCH_SUBMIT 32
57 #define BATCH_COMPLETE 32
58
59 #define BS 4096
60
61 #define MAX_FDS 16
62
63 static unsigned sq_ring_mask, cq_ring_mask;
64
65 struct file {
66 unsigned long max_blocks;
67 unsigned pending_ios;
68 int real_fd;
69 int fixed_fd;
70 };
71
72 struct submitter {
73 pthread_t thread;
74 int ring_fd;
75 struct drand48_data rand;
76 struct io_sq_ring sq_ring;
77 struct io_uring_sqe *sqes;
78 struct iovec iovecs[DEPTH];
79 struct io_cq_ring cq_ring;
80 int inflight;
81 unsigned long reaps;
82 unsigned long done;
83 unsigned long calls;
84 volatile int finish;
85
86 __s32 *fds;
87
88 struct file files[MAX_FDS];
89 unsigned nr_files;
90 unsigned cur_file;
91 };
92
93 static struct submitter submitters[1];
94 static volatile int finish;
95
96 /*
97 * OPTIONS: Set these to test the various features of io_uring.
98 */
99 static int polled = 1; /* use IO polling */
100 static int fixedbufs = 1; /* use fixed user buffers */
101 static int register_files = 1; /* use fixed files */
102 static int buffered = 0; /* use buffered IO, not O_DIRECT */
103 static int sq_thread_poll = 0; /* use kernel submission/poller thread */
104 static int sq_thread_cpu = -1; /* pin above thread to this CPU */
105 static int do_nop = 0; /* no-op SQ ring commands */
106
io_uring_register_buffers(struct submitter * s)107 static int io_uring_register_buffers(struct submitter *s)
108 {
109 if (do_nop)
110 return 0;
111
112 return io_uring_register(s->ring_fd, IORING_REGISTER_BUFFERS, s->iovecs,
113 DEPTH);
114 }
115
io_uring_register_files(struct submitter * s)116 static int io_uring_register_files(struct submitter *s)
117 {
118 unsigned i;
119
120 if (do_nop)
121 return 0;
122
123 s->fds = calloc(s->nr_files, sizeof(__s32));
124 for (i = 0; i < s->nr_files; i++) {
125 s->fds[i] = s->files[i].real_fd;
126 s->files[i].fixed_fd = i;
127 }
128
129 return io_uring_register(s->ring_fd, IORING_REGISTER_FILES, s->fds,
130 s->nr_files);
131 }
132
lk_gettid(void)133 static int lk_gettid(void)
134 {
135 return syscall(__NR_gettid);
136 }
137
file_depth(struct submitter * s)138 static unsigned file_depth(struct submitter *s)
139 {
140 return (DEPTH + s->nr_files - 1) / s->nr_files;
141 }
142
init_io(struct submitter * s,unsigned index)143 static void init_io(struct submitter *s, unsigned index)
144 {
145 struct io_uring_sqe *sqe = &s->sqes[index];
146 unsigned long offset;
147 struct file *f;
148 long r;
149
150 if (do_nop) {
151 sqe->opcode = IORING_OP_NOP;
152 return;
153 }
154
155 if (s->nr_files == 1) {
156 f = &s->files[0];
157 } else {
158 f = &s->files[s->cur_file];
159 if (f->pending_ios >= file_depth(s)) {
160 s->cur_file++;
161 if (s->cur_file == s->nr_files)
162 s->cur_file = 0;
163 f = &s->files[s->cur_file];
164 }
165 }
166 f->pending_ios++;
167
168 lrand48_r(&s->rand, &r);
169 offset = (r % (f->max_blocks - 1)) * BS;
170
171 if (register_files) {
172 sqe->flags = IOSQE_FIXED_FILE;
173 sqe->fd = f->fixed_fd;
174 } else {
175 sqe->flags = 0;
176 sqe->fd = f->real_fd;
177 }
178 if (fixedbufs) {
179 sqe->opcode = IORING_OP_READ_FIXED;
180 sqe->addr = (unsigned long) s->iovecs[index].iov_base;
181 sqe->len = BS;
182 sqe->buf_index = index;
183 } else {
184 sqe->opcode = IORING_OP_READV;
185 sqe->addr = (unsigned long) &s->iovecs[index];
186 sqe->len = 1;
187 sqe->buf_index = 0;
188 }
189 sqe->ioprio = 0;
190 sqe->off = offset;
191 sqe->user_data = (unsigned long) f;
192 }
193
prep_more_ios(struct submitter * s,unsigned max_ios)194 static int prep_more_ios(struct submitter *s, unsigned max_ios)
195 {
196 struct io_sq_ring *ring = &s->sq_ring;
197 unsigned index, tail, next_tail, prepped = 0;
198
199 next_tail = tail = *ring->tail;
200 do {
201 next_tail++;
202 read_barrier();
203 if (next_tail == *ring->head)
204 break;
205
206 index = tail & sq_ring_mask;
207 init_io(s, index);
208 ring->array[index] = index;
209 prepped++;
210 tail = next_tail;
211 } while (prepped < max_ios);
212
213 if (*ring->tail != tail) {
214 /* order tail store with writes to sqes above */
215 write_barrier();
216 *ring->tail = tail;
217 write_barrier();
218 }
219 return prepped;
220 }
221
get_file_size(struct file * f)222 static int get_file_size(struct file *f)
223 {
224 struct stat st;
225
226 if (fstat(f->real_fd, &st) < 0)
227 return -1;
228 if (S_ISBLK(st.st_mode)) {
229 unsigned long long bytes;
230
231 if (ioctl(f->real_fd, BLKGETSIZE64, &bytes) != 0)
232 return -1;
233
234 f->max_blocks = bytes / BS;
235 return 0;
236 } else if (S_ISREG(st.st_mode)) {
237 f->max_blocks = st.st_size / BS;
238 return 0;
239 }
240
241 return -1;
242 }
243
reap_events(struct submitter * s)244 static int reap_events(struct submitter *s)
245 {
246 struct io_cq_ring *ring = &s->cq_ring;
247 struct io_uring_cqe *cqe;
248 unsigned head, reaped = 0;
249
250 head = *ring->head;
251 do {
252 struct file *f;
253
254 read_barrier();
255 if (head == *ring->tail)
256 break;
257 cqe = &ring->cqes[head & cq_ring_mask];
258 if (!do_nop) {
259 f = (struct file *) (uintptr_t) cqe->user_data;
260 f->pending_ios--;
261 if (cqe->res != BS) {
262 printf("io: unexpected ret=%d\n", cqe->res);
263 if (polled && cqe->res == -EOPNOTSUPP)
264 printf("Your filesystem doesn't support poll\n");
265 return -1;
266 }
267 }
268 reaped++;
269 head++;
270 } while (1);
271
272 s->inflight -= reaped;
273 *ring->head = head;
274 write_barrier();
275 return reaped;
276 }
277
submitter_fn(void * data)278 static void *submitter_fn(void *data)
279 {
280 struct submitter *s = data;
281 struct io_sq_ring *ring = &s->sq_ring;
282 int ret, prepped;
283
284 printf("submitter=%d\n", lk_gettid());
285
286 srand48_r(pthread_self(), &s->rand);
287
288 prepped = 0;
289 do {
290 int to_wait, to_submit, this_reap, to_prep;
291
292 if (!prepped && s->inflight < DEPTH) {
293 to_prep = min(DEPTH - s->inflight, BATCH_SUBMIT);
294 prepped = prep_more_ios(s, to_prep);
295 }
296 s->inflight += prepped;
297 submit_more:
298 to_submit = prepped;
299 submit:
300 if (to_submit && (s->inflight + to_submit <= DEPTH))
301 to_wait = 0;
302 else
303 to_wait = min(s->inflight + to_submit, BATCH_COMPLETE);
304
305 /*
306 * Only need to call io_uring_enter if we're not using SQ thread
307 * poll, or if IORING_SQ_NEED_WAKEUP is set.
308 */
309 if (!sq_thread_poll || (*ring->flags & IORING_SQ_NEED_WAKEUP)) {
310 unsigned flags = 0;
311
312 if (to_wait)
313 flags = IORING_ENTER_GETEVENTS;
314 if ((*ring->flags & IORING_SQ_NEED_WAKEUP))
315 flags |= IORING_ENTER_SQ_WAKEUP;
316 ret = io_uring_enter(s->ring_fd, to_submit, to_wait,
317 flags, NULL);
318 s->calls++;
319 }
320
321 /*
322 * For non SQ thread poll, we already got the events we needed
323 * through the io_uring_enter() above. For SQ thread poll, we
324 * need to loop here until we find enough events.
325 */
326 this_reap = 0;
327 do {
328 int r;
329 r = reap_events(s);
330 if (r == -1) {
331 s->finish = 1;
332 break;
333 } else if (r > 0)
334 this_reap += r;
335 } while (sq_thread_poll && this_reap < to_wait);
336 s->reaps += this_reap;
337
338 if (ret >= 0) {
339 if (!ret) {
340 to_submit = 0;
341 if (s->inflight)
342 goto submit;
343 continue;
344 } else if (ret < to_submit) {
345 int diff = to_submit - ret;
346
347 s->done += ret;
348 prepped -= diff;
349 goto submit_more;
350 }
351 s->done += ret;
352 prepped = 0;
353 continue;
354 } else if (ret < 0) {
355 if (errno == EAGAIN) {
356 if (s->finish)
357 break;
358 if (this_reap)
359 goto submit;
360 to_submit = 0;
361 goto submit;
362 }
363 printf("io_submit: %s\n", strerror(errno));
364 break;
365 }
366 } while (!s->finish);
367
368 finish = 1;
369 return NULL;
370 }
371
sig_int(int sig)372 static void sig_int(int sig)
373 {
374 printf("Exiting on signal %d\n", sig);
375 submitters[0].finish = 1;
376 finish = 1;
377 }
378
arm_sig_int(void)379 static void arm_sig_int(void)
380 {
381 struct sigaction act;
382
383 memset(&act, 0, sizeof(act));
384 act.sa_handler = sig_int;
385 act.sa_flags = SA_RESTART;
386 sigaction(SIGINT, &act, NULL);
387 }
388
setup_ring(struct submitter * s)389 static int setup_ring(struct submitter *s)
390 {
391 struct io_sq_ring *sring = &s->sq_ring;
392 struct io_cq_ring *cring = &s->cq_ring;
393 struct io_uring_params p;
394 int ret, fd;
395 void *ptr;
396
397 memset(&p, 0, sizeof(p));
398
399 if (polled && !do_nop)
400 p.flags |= IORING_SETUP_IOPOLL;
401 if (sq_thread_poll) {
402 p.flags |= IORING_SETUP_SQPOLL;
403 if (sq_thread_cpu != -1) {
404 p.flags |= IORING_SETUP_SQ_AFF;
405 p.sq_thread_cpu = sq_thread_cpu;
406 }
407 }
408
409 fd = io_uring_setup(DEPTH, &p);
410 if (fd < 0) {
411 perror("io_uring_setup");
412 return 1;
413 }
414 s->ring_fd = fd;
415
416 if (fixedbufs) {
417 ret = io_uring_register_buffers(s);
418 if (ret < 0) {
419 perror("io_uring_register_buffers");
420 return 1;
421 }
422 }
423
424 if (register_files) {
425 ret = io_uring_register_files(s);
426 if (ret < 0) {
427 perror("io_uring_register_files");
428 return 1;
429 }
430 }
431
432 ptr = mmap(0, p.sq_off.array + p.sq_entries * sizeof(__u32),
433 PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd,
434 IORING_OFF_SQ_RING);
435 printf("sq_ring ptr = 0x%p\n", ptr);
436 sring->head = ptr + p.sq_off.head;
437 sring->tail = ptr + p.sq_off.tail;
438 sring->ring_mask = ptr + p.sq_off.ring_mask;
439 sring->ring_entries = ptr + p.sq_off.ring_entries;
440 sring->flags = ptr + p.sq_off.flags;
441 sring->array = ptr + p.sq_off.array;
442 sq_ring_mask = *sring->ring_mask;
443
444 s->sqes = mmap(0, p.sq_entries * sizeof(struct io_uring_sqe),
445 PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd,
446 IORING_OFF_SQES);
447 printf("sqes ptr = 0x%p\n", s->sqes);
448
449 ptr = mmap(0, p.cq_off.cqes + p.cq_entries * sizeof(struct io_uring_cqe),
450 PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd,
451 IORING_OFF_CQ_RING);
452 printf("cq_ring ptr = 0x%p\n", ptr);
453 cring->head = ptr + p.cq_off.head;
454 cring->tail = ptr + p.cq_off.tail;
455 cring->ring_mask = ptr + p.cq_off.ring_mask;
456 cring->ring_entries = ptr + p.cq_off.ring_entries;
457 cring->cqes = ptr + p.cq_off.cqes;
458 cq_ring_mask = *cring->ring_mask;
459 return 0;
460 }
461
file_depths(char * buf)462 static void file_depths(char *buf)
463 {
464 struct submitter *s = &submitters[0];
465 unsigned i;
466 char *p;
467
468 buf[0] = '\0';
469 p = buf;
470 for (i = 0; i < s->nr_files; i++) {
471 struct file *f = &s->files[i];
472
473 if (i + 1 == s->nr_files)
474 p += sprintf(p, "%d", f->pending_ios);
475 else
476 p += sprintf(p, "%d, ", f->pending_ios);
477 }
478 }
479
main(int argc,char * argv[])480 int main(int argc, char *argv[])
481 {
482 struct submitter *s = &submitters[0];
483 unsigned long done, calls, reap;
484 int err, i, flags, fd;
485 char *fdepths;
486 void *ret;
487
488 if (!do_nop && argc < 2) {
489 printf("%s: filename\n", argv[0]);
490 return 1;
491 }
492
493 flags = O_RDONLY | O_NOATIME;
494 if (!buffered)
495 flags |= O_DIRECT;
496
497 i = 1;
498 while (!do_nop && i < argc) {
499 struct file *f;
500
501 if (s->nr_files == MAX_FDS) {
502 printf("Max number of files (%d) reached\n", MAX_FDS);
503 break;
504 }
505 fd = open(argv[i], flags);
506 if (fd < 0) {
507 perror("open");
508 return 1;
509 }
510
511 f = &s->files[s->nr_files];
512 f->real_fd = fd;
513 if (get_file_size(f)) {
514 printf("failed getting size of device/file\n");
515 return 1;
516 }
517 if (f->max_blocks <= 1) {
518 printf("Zero file/device size?\n");
519 return 1;
520 }
521 f->max_blocks--;
522
523 printf("Added file %s\n", argv[i]);
524 s->nr_files++;
525 i++;
526 }
527
528 if (fixedbufs) {
529 struct rlimit rlim;
530
531 rlim.rlim_cur = RLIM_INFINITY;
532 rlim.rlim_max = RLIM_INFINITY;
533 if (setrlimit(RLIMIT_MEMLOCK, &rlim) < 0) {
534 perror("setrlimit");
535 return 1;
536 }
537 }
538
539 arm_sig_int();
540
541 for (i = 0; i < DEPTH; i++) {
542 void *buf;
543
544 if (posix_memalign(&buf, BS, BS)) {
545 printf("failed alloc\n");
546 return 1;
547 }
548 s->iovecs[i].iov_base = buf;
549 s->iovecs[i].iov_len = BS;
550 }
551
552 err = setup_ring(s);
553 if (err) {
554 printf("ring setup failed: %s, %d\n", strerror(errno), err);
555 return 1;
556 }
557 printf("polled=%d, fixedbufs=%d, buffered=%d", polled, fixedbufs, buffered);
558 printf(" QD=%d, sq_ring=%d, cq_ring=%d\n", DEPTH, *s->sq_ring.ring_entries, *s->cq_ring.ring_entries);
559
560 pthread_create(&s->thread, NULL, submitter_fn, s);
561
562 fdepths = malloc(8 * s->nr_files);
563 reap = calls = done = 0;
564 do {
565 unsigned long this_done = 0;
566 unsigned long this_reap = 0;
567 unsigned long this_call = 0;
568 unsigned long rpc = 0, ipc = 0;
569
570 sleep(1);
571 this_done += s->done;
572 this_call += s->calls;
573 this_reap += s->reaps;
574 if (this_call - calls) {
575 rpc = (this_done - done) / (this_call - calls);
576 ipc = (this_reap - reap) / (this_call - calls);
577 } else
578 rpc = ipc = -1;
579 file_depths(fdepths);
580 printf("IOPS=%lu, IOS/call=%ld/%ld, inflight=%u (%s)\n",
581 this_done - done, rpc, ipc, s->inflight,
582 fdepths);
583 done = this_done;
584 calls = this_call;
585 reap = this_reap;
586 } while (!finish);
587
588 pthread_join(s->thread, &ret);
589 close(s->ring_fd);
590 free(fdepths);
591 return 0;
592 }
593