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// 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))
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