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authorJens Axboe <axboe@kernel.dk>2019-03-06 09:03:50 -0700
committerJens Axboe <axboe@kernel.dk>2019-03-06 13:00:16 -0700
commit21b4aa5d20fd07207e73270cadffed5c63fb4343 (patch)
treef9efcd15b170905dd1d9a4f1801b26b0ec90c34e /tools/io_uring/io_uring-bench.c
parent31b515106428b9717d2b6475b6f6182cf231b1e6 (diff)
downloadlinux-21b4aa5d20fd07207e73270cadffed5c63fb4343.tar.bz2
io_uring: add a few test tools
This adds two test programs in tools/io_uring/ that demonstrate both the raw io_uring API (and all features) through a small benchmark app, io_uring-bench, and the liburing exposed API in a simplified cp(1) implementation through io_uring-cp. Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'tools/io_uring/io_uring-bench.c')
-rw-r--r--tools/io_uring/io_uring-bench.c616
1 files changed, 616 insertions, 0 deletions
diff --git a/tools/io_uring/io_uring-bench.c b/tools/io_uring/io_uring-bench.c
new file mode 100644
index 000000000000..512306a37531
--- /dev/null
+++ b/tools/io_uring/io_uring-bench.c
@@ -0,0 +1,616 @@
+// 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"
+
+#ifndef IOCQE_FLAG_CACHEHIT
+#define IOCQE_FLAG_CACHEHIT (1U << 0)
+#endif
+
+#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;
+ unsigned long cachehit, cachemiss;
+ 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;
+ }
+ }
+ if (cqe->flags & IOCQE_FLAG_CACHEHIT)
+ s->cachehit++;
+ else
+ s->cachemiss++;
+ 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, cache_hit, cache_miss;
+ 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);
+ cache_hit = cache_miss = reap = calls = done = 0;
+ do {
+ unsigned long this_done = 0;
+ unsigned long this_reap = 0;
+ unsigned long this_call = 0;
+ unsigned long this_cache_hit = 0;
+ unsigned long this_cache_miss = 0;
+ unsigned long rpc = 0, ipc = 0;
+ double hit = 0.0;
+
+ sleep(1);
+ this_done += s->done;
+ this_call += s->calls;
+ this_reap += s->reaps;
+ this_cache_hit += s->cachehit;
+ this_cache_miss += s->cachemiss;
+ if (this_cache_hit && this_cache_miss) {
+ unsigned long hits, total;
+
+ hits = this_cache_hit - cache_hit;
+ total = hits + this_cache_miss - cache_miss;
+ hit = (double) hits / (double) total;
+ hit *= 100.0;
+ }
+ 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), Cachehit=%0.2f%%\n",
+ this_done - done, rpc, ipc, s->inflight,
+ fdepths, hit);
+ done = this_done;
+ calls = this_call;
+ reap = this_reap;
+ cache_hit = s->cachehit;
+ cache_miss = s->cachemiss;
+ } while (!finish);
+
+ pthread_join(s->thread, &ret);
+ close(s->ring_fd);
+ free(fdepths);
+ return 0;
+}