// 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 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", 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; }