diff options
Diffstat (limited to 'tools/io_uring')
| -rw-r--r-- | tools/io_uring/Makefile | 18 | ||||
| -rw-r--r-- | tools/io_uring/README | 29 | ||||
| -rw-r--r-- | tools/io_uring/barrier.h | 16 | ||||
| -rw-r--r-- | tools/io_uring/io_uring-bench.c | 592 | ||||
| -rw-r--r-- | tools/io_uring/io_uring-cp.c | 283 | ||||
| -rw-r--r-- | tools/io_uring/liburing.h | 187 | ||||
| -rw-r--r-- | tools/io_uring/queue.c | 156 | ||||
| -rw-r--r-- | tools/io_uring/setup.c | 107 | ||||
| -rw-r--r-- | tools/io_uring/syscall.c | 52 |
9 files changed, 1440 insertions, 0 deletions
diff --git a/tools/io_uring/Makefile b/tools/io_uring/Makefile new file mode 100644 index 000000000..00f146c54 --- /dev/null +++ b/tools/io_uring/Makefile @@ -0,0 +1,18 @@ +# SPDX-License-Identifier: GPL-2.0 +# Makefile for io_uring test tools +CFLAGS += -Wall -Wextra -g -D_GNU_SOURCE +LDLIBS += -lpthread + +all: io_uring-cp io_uring-bench +%: %.c + $(CC) $(CFLAGS) -o $@ $^ + +io_uring-bench: syscall.o io_uring-bench.o + $(CC) $(CFLAGS) -o $@ $^ $(LDLIBS) + +io_uring-cp: setup.o syscall.o queue.o + +clean: + $(RM) io_uring-cp io_uring-bench *.o + +.PHONY: all clean diff --git a/tools/io_uring/README b/tools/io_uring/README new file mode 100644 index 000000000..67fd70115 --- /dev/null +++ b/tools/io_uring/README @@ -0,0 +1,29 @@ +This directory includes a few programs that demonstrate how to use io_uring +in an application. The examples are: + +io_uring-cp + A very basic io_uring implementation of cp(1). It takes two + arguments, copies the first argument to the second. This example + is part of liburing, and hence uses the simplified liburing API + for setting up an io_uring instance, submitting IO, completing IO, + etc. The support functions in queue.c and setup.c are straight + out of liburing. + +io_uring-bench + Benchmark program that does random reads on a number of files. This + app demonstrates the various features of io_uring, like fixed files, + fixed buffers, and polled IO. There are options in the program to + control which features to use. Arguments is the file (or files) that + io_uring-bench should operate on. This uses the raw io_uring + interface. + +liburing can be cloned with git here: + + git://git.kernel.dk/liburing + +and contains a number of unit tests as well for testing io_uring. It also +comes with man pages for the three system calls. + +Fio includes an io_uring engine, you can clone fio here: + + git://git.kernel.dk/fio diff --git a/tools/io_uring/barrier.h b/tools/io_uring/barrier.h new file mode 100644 index 000000000..ef00f6722 --- /dev/null +++ b/tools/io_uring/barrier.h @@ -0,0 +1,16 @@ +#ifndef LIBURING_BARRIER_H +#define LIBURING_BARRIER_H + +#if defined(__x86_64) || defined(__i386__) +#define read_barrier() __asm__ __volatile__("":::"memory") +#define write_barrier() __asm__ __volatile__("":::"memory") +#else +/* + * Add arch appropriate definitions. Be safe and use full barriers for + * archs we don't have support for. + */ +#define read_barrier() __sync_synchronize() +#define write_barrier() __sync_synchronize() +#endif + +#endif diff --git a/tools/io_uring/io_uring-bench.c b/tools/io_uring/io_uring-bench.c new file mode 100644 index 000000000..7703f0118 --- /dev/null +++ b/tools/io_uring/io_uring-bench.c @@ -0,0 +1,592 @@ +// 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; +} diff --git a/tools/io_uring/io_uring-cp.c b/tools/io_uring/io_uring-cp.c new file mode 100644 index 000000000..d9bd6f5f8 --- /dev/null +++ b/tools/io_uring/io_uring-cp.c @@ -0,0 +1,283 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Simple test program that demonstrates a file copy through io_uring. This + * uses the API exposed by liburing. + * + * Copyright (C) 2018-2019 Jens Axboe + */ +#include <stdio.h> +#include <fcntl.h> +#include <string.h> +#include <stdlib.h> +#include <unistd.h> +#include <assert.h> +#include <errno.h> +#include <inttypes.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/ioctl.h> + +#include "liburing.h" + +#define QD 64 +#define BS (32*1024) + +static int infd, outfd; + +struct io_data { + int read; + off_t first_offset, offset; + size_t first_len; + struct iovec iov; +}; + +static int setup_context(unsigned entries, struct io_uring *ring) +{ + int ret; + + ret = io_uring_queue_init(entries, ring, 0); + if (ret < 0) { + fprintf(stderr, "queue_init: %s\n", strerror(-ret)); + return -1; + } + + return 0; +} + +static int get_file_size(int fd, off_t *size) +{ + struct stat st; + + if (fstat(fd, &st) < 0) + return -1; + if (S_ISREG(st.st_mode)) { + *size = st.st_size; + return 0; + } else if (S_ISBLK(st.st_mode)) { + unsigned long long bytes; + + if (ioctl(fd, BLKGETSIZE64, &bytes) != 0) + return -1; + + *size = bytes; + return 0; + } + + return -1; +} + +static void queue_prepped(struct io_uring *ring, struct io_data *data) +{ + struct io_uring_sqe *sqe; + + sqe = io_uring_get_sqe(ring); + assert(sqe); + + if (data->read) + io_uring_prep_readv(sqe, infd, &data->iov, 1, data->offset); + else + io_uring_prep_writev(sqe, outfd, &data->iov, 1, data->offset); + + io_uring_sqe_set_data(sqe, data); +} + +static int queue_read(struct io_uring *ring, off_t size, off_t offset) +{ + struct io_uring_sqe *sqe; + struct io_data *data; + + data = malloc(size + sizeof(*data)); + if (!data) + return 1; + + sqe = io_uring_get_sqe(ring); + if (!sqe) { + free(data); + return 1; + } + + data->read = 1; + data->offset = data->first_offset = offset; + + data->iov.iov_base = data + 1; + data->iov.iov_len = size; + data->first_len = size; + + io_uring_prep_readv(sqe, infd, &data->iov, 1, offset); + io_uring_sqe_set_data(sqe, data); + return 0; +} + +static void queue_write(struct io_uring *ring, struct io_data *data) +{ + data->read = 0; + data->offset = data->first_offset; + + data->iov.iov_base = data + 1; + data->iov.iov_len = data->first_len; + + queue_prepped(ring, data); + io_uring_submit(ring); +} + +static int copy_file(struct io_uring *ring, off_t insize) +{ + unsigned long reads, writes; + struct io_uring_cqe *cqe; + off_t write_left, offset; + int ret; + + write_left = insize; + writes = reads = offset = 0; + + while (insize || write_left) { + int had_reads, got_comp; + + /* + * Queue up as many reads as we can + */ + had_reads = reads; + while (insize) { + off_t this_size = insize; + + if (reads + writes >= QD) + break; + if (this_size > BS) + this_size = BS; + else if (!this_size) + break; + + if (queue_read(ring, this_size, offset)) + break; + + insize -= this_size; + offset += this_size; + reads++; + } + + if (had_reads != reads) { + ret = io_uring_submit(ring); + if (ret < 0) { + fprintf(stderr, "io_uring_submit: %s\n", strerror(-ret)); + break; + } + } + + /* + * Queue is full at this point. Find at least one completion. + */ + got_comp = 0; + while (write_left) { + struct io_data *data; + + if (!got_comp) { + ret = io_uring_wait_cqe(ring, &cqe); + got_comp = 1; + } else { + ret = io_uring_peek_cqe(ring, &cqe); + if (ret == -EAGAIN) { + cqe = NULL; + ret = 0; + } + } + if (ret < 0) { + fprintf(stderr, "io_uring_peek_cqe: %s\n", + strerror(-ret)); + return 1; + } + if (!cqe) + break; + + data = io_uring_cqe_get_data(cqe); + if (cqe->res < 0) { + if (cqe->res == -EAGAIN) { + queue_prepped(ring, data); + io_uring_cqe_seen(ring, cqe); + continue; + } + fprintf(stderr, "cqe failed: %s\n", + strerror(-cqe->res)); + return 1; + } else if (cqe->res != data->iov.iov_len) { + /* Short read/write, adjust and requeue */ + data->iov.iov_base += cqe->res; + data->iov.iov_len -= cqe->res; + data->offset += cqe->res; + queue_prepped(ring, data); + io_uring_cqe_seen(ring, cqe); + continue; + } + + /* + * All done. if write, nothing else to do. if read, + * queue up corresponding write. + */ + if (data->read) { + queue_write(ring, data); + write_left -= data->first_len; + reads--; + writes++; + } else { + free(data); + writes--; + } + io_uring_cqe_seen(ring, cqe); + } + } + + /* wait out pending writes */ + while (writes) { + struct io_data *data; + + ret = io_uring_wait_cqe(ring, &cqe); + if (ret) { + fprintf(stderr, "wait_cqe=%d\n", ret); + return 1; + } + if (cqe->res < 0) { + fprintf(stderr, "write res=%d\n", cqe->res); + return 1; + } + data = io_uring_cqe_get_data(cqe); + free(data); + writes--; + io_uring_cqe_seen(ring, cqe); + } + + return 0; +} + +int main(int argc, char *argv[]) +{ + struct io_uring ring; + off_t insize; + int ret; + + if (argc < 3) { + printf("%s: infile outfile\n", argv[0]); + return 1; + } + + infd = open(argv[1], O_RDONLY); + if (infd < 0) { + perror("open infile"); + return 1; + } + outfd = open(argv[2], O_WRONLY | O_CREAT | O_TRUNC, 0644); + if (outfd < 0) { + perror("open outfile"); + return 1; + } + + if (setup_context(QD, &ring)) + return 1; + if (get_file_size(infd, &insize)) + return 1; + + ret = copy_file(&ring, insize); + + close(infd); + close(outfd); + io_uring_queue_exit(&ring); + return ret; +} diff --git a/tools/io_uring/liburing.h b/tools/io_uring/liburing.h new file mode 100644 index 000000000..28a837b60 --- /dev/null +++ b/tools/io_uring/liburing.h @@ -0,0 +1,187 @@ +#ifndef LIB_URING_H +#define LIB_URING_H + +#ifdef __cplusplus +extern "C" { +#endif + +#include <sys/uio.h> +#include <signal.h> +#include <string.h> +#include "../../include/uapi/linux/io_uring.h" +#include <inttypes.h> +#include <linux/swab.h> +#include "barrier.h" + +/* + * Library interface to io_uring + */ +struct io_uring_sq { + unsigned *khead; + unsigned *ktail; + unsigned *kring_mask; + unsigned *kring_entries; + unsigned *kflags; + unsigned *kdropped; + unsigned *array; + struct io_uring_sqe *sqes; + + unsigned sqe_head; + unsigned sqe_tail; + + size_t ring_sz; +}; + +struct io_uring_cq { + unsigned *khead; + unsigned *ktail; + unsigned *kring_mask; + unsigned *kring_entries; + unsigned *koverflow; + struct io_uring_cqe *cqes; + + size_t ring_sz; +}; + +struct io_uring { + struct io_uring_sq sq; + struct io_uring_cq cq; + int ring_fd; +}; + +/* + * System calls + */ +extern int io_uring_setup(unsigned entries, struct io_uring_params *p); +extern int io_uring_enter(int fd, unsigned to_submit, + unsigned min_complete, unsigned flags, sigset_t *sig); +extern int io_uring_register(int fd, unsigned int opcode, void *arg, + unsigned int nr_args); + +/* + * Library interface + */ +extern int io_uring_queue_init(unsigned entries, struct io_uring *ring, + unsigned flags); +extern int io_uring_queue_mmap(int fd, struct io_uring_params *p, + struct io_uring *ring); +extern void io_uring_queue_exit(struct io_uring *ring); +extern int io_uring_peek_cqe(struct io_uring *ring, + struct io_uring_cqe **cqe_ptr); +extern int io_uring_wait_cqe(struct io_uring *ring, + struct io_uring_cqe **cqe_ptr); +extern int io_uring_submit(struct io_uring *ring); +extern struct io_uring_sqe *io_uring_get_sqe(struct io_uring *ring); + +/* + * Must be called after io_uring_{peek,wait}_cqe() after the cqe has + * been processed by the application. + */ +static inline void io_uring_cqe_seen(struct io_uring *ring, + struct io_uring_cqe *cqe) +{ + if (cqe) { + struct io_uring_cq *cq = &ring->cq; + + (*cq->khead)++; + /* + * Ensure that the kernel sees our new head, the kernel has + * the matching read barrier. + */ + write_barrier(); + } +} + +/* + * Command prep helpers + */ +static inline void io_uring_sqe_set_data(struct io_uring_sqe *sqe, void *data) +{ + sqe->user_data = (unsigned long) data; +} + +static inline void *io_uring_cqe_get_data(struct io_uring_cqe *cqe) +{ + return (void *) (uintptr_t) cqe->user_data; +} + +static inline void io_uring_prep_rw(int op, struct io_uring_sqe *sqe, int fd, + const void *addr, unsigned len, + off_t offset) +{ + memset(sqe, 0, sizeof(*sqe)); + sqe->opcode = op; + sqe->fd = fd; + sqe->off = offset; + sqe->addr = (unsigned long) addr; + sqe->len = len; +} + +static inline void io_uring_prep_readv(struct io_uring_sqe *sqe, int fd, + const struct iovec *iovecs, + unsigned nr_vecs, off_t offset) +{ + io_uring_prep_rw(IORING_OP_READV, sqe, fd, iovecs, nr_vecs, offset); +} + +static inline void io_uring_prep_read_fixed(struct io_uring_sqe *sqe, int fd, + void *buf, unsigned nbytes, + off_t offset) +{ + io_uring_prep_rw(IORING_OP_READ_FIXED, sqe, fd, buf, nbytes, offset); +} + +static inline void io_uring_prep_writev(struct io_uring_sqe *sqe, int fd, + const struct iovec *iovecs, + unsigned nr_vecs, off_t offset) +{ + io_uring_prep_rw(IORING_OP_WRITEV, sqe, fd, iovecs, nr_vecs, offset); +} + +static inline void io_uring_prep_write_fixed(struct io_uring_sqe *sqe, int fd, + const void *buf, unsigned nbytes, + off_t offset) +{ + io_uring_prep_rw(IORING_OP_WRITE_FIXED, sqe, fd, buf, nbytes, offset); +} + +static inline void io_uring_prep_poll_add(struct io_uring_sqe *sqe, int fd, + unsigned poll_mask) +{ + memset(sqe, 0, sizeof(*sqe)); + sqe->opcode = IORING_OP_POLL_ADD; + sqe->fd = fd; +#if __BYTE_ORDER == __BIG_ENDIAN + poll_mask = __swahw32(poll_mask); +#endif + sqe->poll_events = poll_mask; +} + +static inline void io_uring_prep_poll_remove(struct io_uring_sqe *sqe, + void *user_data) +{ + memset(sqe, 0, sizeof(*sqe)); + sqe->opcode = IORING_OP_POLL_REMOVE; + sqe->addr = (unsigned long) user_data; +} + +static inline void io_uring_prep_fsync(struct io_uring_sqe *sqe, int fd, + unsigned fsync_flags) +{ + memset(sqe, 0, sizeof(*sqe)); + sqe->opcode = IORING_OP_FSYNC; + sqe->fd = fd; + sqe->fsync_flags = fsync_flags; +} + +static inline void io_uring_prep_nop(struct io_uring_sqe *sqe) +{ + memset(sqe, 0, sizeof(*sqe)); + sqe->opcode = IORING_OP_NOP; +} + +#ifdef __cplusplus +} +#endif + +#endif diff --git a/tools/io_uring/queue.c b/tools/io_uring/queue.c new file mode 100644 index 000000000..321819c13 --- /dev/null +++ b/tools/io_uring/queue.c @@ -0,0 +1,156 @@ +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/mman.h> +#include <unistd.h> +#include <errno.h> +#include <string.h> + +#include "liburing.h" +#include "barrier.h" + +static int __io_uring_get_cqe(struct io_uring *ring, + struct io_uring_cqe **cqe_ptr, int wait) +{ + struct io_uring_cq *cq = &ring->cq; + const unsigned mask = *cq->kring_mask; + unsigned head; + int ret; + + *cqe_ptr = NULL; + head = *cq->khead; + do { + /* + * It's necessary to use a read_barrier() before reading + * the CQ tail, since the kernel updates it locklessly. The + * kernel has the matching store barrier for the update. The + * kernel also ensures that previous stores to CQEs are ordered + * with the tail update. + */ + read_barrier(); + if (head != *cq->ktail) { + *cqe_ptr = &cq->cqes[head & mask]; + break; + } + if (!wait) + break; + ret = io_uring_enter(ring->ring_fd, 0, 1, + IORING_ENTER_GETEVENTS, NULL); + if (ret < 0) + return -errno; + } while (1); + + return 0; +} + +/* + * Return an IO completion, if one is readily available. Returns 0 with + * cqe_ptr filled in on success, -errno on failure. + */ +int io_uring_peek_cqe(struct io_uring *ring, struct io_uring_cqe **cqe_ptr) +{ + return __io_uring_get_cqe(ring, cqe_ptr, 0); +} + +/* + * Return an IO completion, waiting for it if necessary. Returns 0 with + * cqe_ptr filled in on success, -errno on failure. + */ +int io_uring_wait_cqe(struct io_uring *ring, struct io_uring_cqe **cqe_ptr) +{ + return __io_uring_get_cqe(ring, cqe_ptr, 1); +} + +/* + * Submit sqes acquired from io_uring_get_sqe() to the kernel. + * + * Returns number of sqes submitted + */ +int io_uring_submit(struct io_uring *ring) +{ + struct io_uring_sq *sq = &ring->sq; + const unsigned mask = *sq->kring_mask; + unsigned ktail, ktail_next, submitted, to_submit; + int ret; + + /* + * If we have pending IO in the kring, submit it first. We need a + * read barrier here to match the kernels store barrier when updating + * the SQ head. + */ + read_barrier(); + if (*sq->khead != *sq->ktail) { + submitted = *sq->kring_entries; + goto submit; + } + + if (sq->sqe_head == sq->sqe_tail) + return 0; + + /* + * Fill in sqes that we have queued up, adding them to the kernel ring + */ + submitted = 0; + ktail = ktail_next = *sq->ktail; + to_submit = sq->sqe_tail - sq->sqe_head; + while (to_submit--) { + ktail_next++; + read_barrier(); + + sq->array[ktail & mask] = sq->sqe_head & mask; + ktail = ktail_next; + + sq->sqe_head++; + submitted++; + } + + if (!submitted) + return 0; + + if (*sq->ktail != ktail) { + /* + * First write barrier ensures that the SQE stores are updated + * with the tail update. This is needed so that the kernel + * will never see a tail update without the preceeding sQE + * stores being done. + */ + write_barrier(); + *sq->ktail = ktail; + /* + * The kernel has the matching read barrier for reading the + * SQ tail. + */ + write_barrier(); + } + +submit: + ret = io_uring_enter(ring->ring_fd, submitted, 0, + IORING_ENTER_GETEVENTS, NULL); + if (ret < 0) + return -errno; + + return ret; +} + +/* + * Return an sqe to fill. Application must later call io_uring_submit() + * when it's ready to tell the kernel about it. The caller may call this + * function multiple times before calling io_uring_submit(). + * + * Returns a vacant sqe, or NULL if we're full. + */ +struct io_uring_sqe *io_uring_get_sqe(struct io_uring *ring) +{ + struct io_uring_sq *sq = &ring->sq; + unsigned next = sq->sqe_tail + 1; + struct io_uring_sqe *sqe; + + /* + * All sqes are used + */ + if (next - sq->sqe_head > *sq->kring_entries) + return NULL; + + sqe = &sq->sqes[sq->sqe_tail & *sq->kring_mask]; + sq->sqe_tail = next; + return sqe; +} diff --git a/tools/io_uring/setup.c b/tools/io_uring/setup.c new file mode 100644 index 000000000..0b50fcd78 --- /dev/null +++ b/tools/io_uring/setup.c @@ -0,0 +1,107 @@ +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/mman.h> +#include <unistd.h> +#include <errno.h> +#include <string.h> + +#include "liburing.h" + +static int io_uring_mmap(int fd, struct io_uring_params *p, + struct io_uring_sq *sq, struct io_uring_cq *cq) +{ + size_t size; + void *ptr; + int ret; + + sq->ring_sz = p->sq_off.array + p->sq_entries * sizeof(unsigned); + ptr = mmap(0, sq->ring_sz, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_SQ_RING); + if (ptr == MAP_FAILED) + return -errno; + sq->khead = ptr + p->sq_off.head; + sq->ktail = ptr + p->sq_off.tail; + sq->kring_mask = ptr + p->sq_off.ring_mask; + sq->kring_entries = ptr + p->sq_off.ring_entries; + sq->kflags = ptr + p->sq_off.flags; + sq->kdropped = ptr + p->sq_off.dropped; + sq->array = ptr + p->sq_off.array; + + size = p->sq_entries * sizeof(struct io_uring_sqe); + sq->sqes = mmap(0, size, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_POPULATE, fd, + IORING_OFF_SQES); + if (sq->sqes == MAP_FAILED) { + ret = -errno; +err: + munmap(sq->khead, sq->ring_sz); + return ret; + } + + cq->ring_sz = p->cq_off.cqes + p->cq_entries * sizeof(struct io_uring_cqe); + ptr = mmap(0, cq->ring_sz, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_CQ_RING); + if (ptr == MAP_FAILED) { + ret = -errno; + munmap(sq->sqes, p->sq_entries * sizeof(struct io_uring_sqe)); + goto err; + } + cq->khead = ptr + p->cq_off.head; + cq->ktail = ptr + p->cq_off.tail; + cq->kring_mask = ptr + p->cq_off.ring_mask; + cq->kring_entries = ptr + p->cq_off.ring_entries; + cq->koverflow = ptr + p->cq_off.overflow; + cq->cqes = ptr + p->cq_off.cqes; + return 0; +} + +/* + * For users that want to specify sq_thread_cpu or sq_thread_idle, this + * interface is a convenient helper for mmap()ing the rings. + * Returns -1 on error, or zero on success. On success, 'ring' + * contains the necessary information to read/write to the rings. + */ +int io_uring_queue_mmap(int fd, struct io_uring_params *p, struct io_uring *ring) +{ + int ret; + + memset(ring, 0, sizeof(*ring)); + ret = io_uring_mmap(fd, p, &ring->sq, &ring->cq); + if (!ret) + ring->ring_fd = fd; + return ret; +} + +/* + * Returns -1 on error, or zero on success. On success, 'ring' + * contains the necessary information to read/write to the rings. + */ +int io_uring_queue_init(unsigned entries, struct io_uring *ring, unsigned flags) +{ + struct io_uring_params p; + int fd, ret; + + memset(&p, 0, sizeof(p)); + p.flags = flags; + + fd = io_uring_setup(entries, &p); + if (fd < 0) + return fd; + + ret = io_uring_queue_mmap(fd, &p, ring); + if (ret) + close(fd); + + return ret; +} + +void io_uring_queue_exit(struct io_uring *ring) +{ + struct io_uring_sq *sq = &ring->sq; + struct io_uring_cq *cq = &ring->cq; + + munmap(sq->sqes, *sq->kring_entries * sizeof(struct io_uring_sqe)); + munmap(sq->khead, sq->ring_sz); + munmap(cq->khead, cq->ring_sz); + close(ring->ring_fd); +} diff --git a/tools/io_uring/syscall.c b/tools/io_uring/syscall.c new file mode 100644 index 000000000..b22e0aa54 --- /dev/null +++ b/tools/io_uring/syscall.c @@ -0,0 +1,52 @@ +/* + * Will go away once libc support is there + */ +#include <unistd.h> +#include <sys/syscall.h> +#include <sys/uio.h> +#include <signal.h> +#include "liburing.h" + +#ifdef __alpha__ +/* + * alpha is the only exception, all other architectures + * have common numbers for new system calls. + */ +# ifndef __NR_io_uring_setup +# define __NR_io_uring_setup 535 +# endif +# ifndef __NR_io_uring_enter +# define __NR_io_uring_enter 536 +# endif +# ifndef __NR_io_uring_register +# define __NR_io_uring_register 537 +# endif +#else /* !__alpha__ */ +# ifndef __NR_io_uring_setup +# define __NR_io_uring_setup 425 +# endif +# ifndef __NR_io_uring_enter +# define __NR_io_uring_enter 426 +# endif +# ifndef __NR_io_uring_register +# define __NR_io_uring_register 427 +# endif +#endif + +int io_uring_register(int fd, unsigned int opcode, void *arg, + unsigned int nr_args) +{ + return syscall(__NR_io_uring_register, fd, opcode, arg, nr_args); +} + +int io_uring_setup(unsigned int entries, struct io_uring_params *p) +{ + return syscall(__NR_io_uring_setup, entries, p); +} + +int io_uring_enter(int fd, unsigned int to_submit, unsigned int min_complete, + unsigned int flags, sigset_t *sig) +{ + return syscall(__NR_io_uring_enter, fd, to_submit, min_complete, + flags, sig, _NSIG / 8); +} |