/*
* io_uring engine
*
* IO engine using the new native Linux aio io_uring interface. See:
*
* http://git.kernel.dk/cgit/linux-block/log/?h=io_uring
*
*/
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/time.h>
#include <sys/resource.h>
#include "../fio.h"
#include "../lib/pow2.h"
#include "../optgroup.h"
#include "../lib/memalign.h"
#include "../lib/fls.h"
#ifdef ARCH_HAVE_IOURING
#include "../lib/types.h"
#include "../os/linux/io_uring.h"
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;
};
struct ioring_mmap {
void *ptr;
size_t len;
};
struct ioring_data {
int ring_fd;
struct io_u **io_u_index;
int *fds;
struct io_sq_ring sq_ring;
struct io_uring_sqe *sqes;
struct iovec *iovecs;
unsigned sq_ring_mask;
struct io_cq_ring cq_ring;
unsigned cq_ring_mask;
int queued;
int cq_ring_off;
unsigned iodepth;
bool ioprio_class_set;
bool ioprio_set;
struct ioring_mmap mmap[3];
};
struct ioring_options {
void *pad;
unsigned int hipri;
unsigned int cmdprio_percentage;
unsigned int fixedbufs;
unsigned int registerfiles;
unsigned int sqpoll_thread;
unsigned int sqpoll_set;
unsigned int sqpoll_cpu;
unsigned int nonvectored;
unsigned int uncached;
};
static const int ddir_to_op[2][2] = {
{ IORING_OP_READV, IORING_OP_READ },
{ IORING_OP_WRITEV, IORING_OP_WRITE }
};
static const int fixed_ddir_to_op[2] = {
IORING_OP_READ_FIXED,
IORING_OP_WRITE_FIXED
};
static int fio_ioring_sqpoll_cb(void *data, unsigned long long *val)
{
struct ioring_options *o = data;
o->sqpoll_cpu = *val;
o->sqpoll_set = 1;
return 0;
}
static struct fio_option options[] = {
{
.name = "hipri",
.lname = "High Priority",
.type = FIO_OPT_STR_SET,
.off1 = offsetof(struct ioring_options, hipri),
.help = "Use polled IO completions",
.category = FIO_OPT_C_ENGINE,
.group = FIO_OPT_G_IOURING,
},
#ifdef FIO_HAVE_IOPRIO_CLASS
{
.name = "cmdprio_percentage",
.lname = "high priority percentage",
.type = FIO_OPT_INT,
.off1 = offsetof(struct ioring_options, cmdprio_percentage),
.minval = 1,
.maxval = 100,
.help = "Send high priority I/O this percentage of the time",
.category = FIO_OPT_C_ENGINE,
.group = FIO_OPT_G_IOURING,
},
#else
{
.name = "cmdprio_percentage",
.lname = "high priority percentage",
.type = FIO_OPT_UNSUPPORTED,
.help = "Your platform does not support I/O priority classes",
},
#endif
{
.name = "fixedbufs",
.lname = "Fixed (pre-mapped) IO buffers",
.type = FIO_OPT_STR_SET,
.off1 = offsetof(struct ioring_options, fixedbufs),
.help = "Pre map IO buffers",
.category = FIO_OPT_C_ENGINE,
.group = FIO_OPT_G_IOURING,
},
{
.name = "registerfiles",
.lname = "Register file set",
.type = FIO_OPT_STR_SET,
.off1 = offsetof(struct ioring_options, registerfiles),
.help = "Pre-open/register files",
.category = FIO_OPT_C_ENGINE,
.group = FIO_OPT_G_IOURING,
},
{
.name = "sqthread_poll",
.lname = "Kernel SQ thread polling",
.type = FIO_OPT_INT,
.off1 = offsetof(struct ioring_options, sqpoll_thread),
.help = "Offload submission/completion to kernel thread",
.category = FIO_OPT_C_ENGINE,
.group = FIO_OPT_G_IOURING,
},
{
.name = "sqthread_poll_cpu",
.lname = "SQ Thread Poll CPU",
.type = FIO_OPT_INT,
.cb = fio_ioring_sqpoll_cb,
.help = "What CPU to run SQ thread polling on",
.category = FIO_OPT_C_ENGINE,
.group = FIO_OPT_G_IOURING,
},
{
.name = "nonvectored",
.lname = "Non-vectored",
.type = FIO_OPT_INT,
.off1 = offsetof(struct ioring_options, nonvectored),
.help = "Use non-vectored read/write commands",
.category = FIO_OPT_C_ENGINE,
.group = FIO_OPT_G_IOURING,
},
{
.name = "uncached",
.lname = "Uncached",
.type = FIO_OPT_INT,
.off1 = offsetof(struct ioring_options, uncached),
.help = "Use RWF_UNCACHED for buffered read/writes",
.category = FIO_OPT_C_ENGINE,
.group = FIO_OPT_G_IOURING,
},
{
.name = NULL,
},
};
static int io_uring_enter(struct ioring_data *ld, unsigned int to_submit,
unsigned int min_complete, unsigned int flags)
{
return syscall(__NR_io_uring_enter, ld->ring_fd, to_submit,
min_complete, flags, NULL, 0);
}
static int fio_ioring_prep(struct thread_data *td, struct io_u *io_u)
{
struct ioring_data *ld = td->io_ops_data;
struct ioring_options *o = td->eo;
struct fio_file *f = io_u->file;
struct io_uring_sqe *sqe;
sqe = &ld->sqes[io_u->index];
/* zero out fields not used in this submission */
memset(sqe, 0, sizeof(*sqe));
if (o->registerfiles) {
sqe->fd = f->engine_pos;
sqe->flags = IOSQE_FIXED_FILE;
} else {
sqe->fd = f->fd;
}
if (io_u->ddir == DDIR_READ || io_u->ddir == DDIR_WRITE) {
if (o->fixedbufs) {
sqe->opcode = fixed_ddir_to_op[io_u->ddir];
sqe->addr = (unsigned long) io_u->xfer_buf;
sqe->len = io_u->xfer_buflen;
sqe->buf_index = io_u->index;
} else {
sqe->opcode = ddir_to_op[io_u->ddir][!!o->nonvectored];
if (o->nonvectored) {
sqe->addr = (unsigned long)
ld->iovecs[io_u->index].iov_base;
sqe->len = ld->iovecs[io_u->index].iov_len;
} else {
sqe->addr = (unsigned long) &ld->iovecs[io_u->index];
sqe->len = 1;
}
}
if (!td->o.odirect && o->uncached)
sqe->rw_flags = RWF_UNCACHED;
if (ld->ioprio_class_set)
sqe->ioprio = td->o.ioprio_class << 13;
if (ld->ioprio_set)
sqe->ioprio |= td->o.ioprio;
sqe->off = io_u->offset;
} else if (ddir_sync(io_u->ddir)) {
if (io_u->ddir == DDIR_SYNC_FILE_RANGE) {
sqe->off = f->first_write;
sqe->len = f->last_write - f->first_write;
sqe->sync_range_flags = td->o.sync_file_range;
sqe->opcode = IORING_OP_SYNC_FILE_RANGE;
} else {
if (io_u->ddir == DDIR_DATASYNC)
sqe->fsync_flags |= IORING_FSYNC_DATASYNC;
sqe->opcode = IORING_OP_FSYNC;
}
}
sqe->user_data = (unsigned long) io_u;
return 0;
}
static struct io_u *fio_ioring_event(struct thread_data *td, int event)
{
struct ioring_data *ld = td->io_ops_data;
struct io_uring_cqe *cqe;
struct io_u *io_u;
unsigned index;
index = (event + ld->cq_ring_off) & ld->cq_ring_mask;
cqe = &ld->cq_ring.cqes[index];
io_u = (struct io_u *) (uintptr_t) cqe->user_data;
if (cqe->res != io_u->xfer_buflen) {
if (cqe->res > io_u->xfer_buflen)
io_u->error = -cqe->res;
else
io_u->resid = io_u->xfer_buflen - cqe->res;
} else
io_u->error = 0;
return io_u;
}
static int fio_ioring_cqring_reap(struct thread_data *td, unsigned int events,
unsigned int max)
{
struct ioring_data *ld = td->io_ops_data;
struct io_cq_ring *ring = &ld->cq_ring;
unsigned head, reaped = 0;
head = *ring->head;
do {
read_barrier();
if (head == *ring->tail)
break;
reaped++;
head++;
} while (reaped + events < max);
*ring->head = head;
write_barrier();
return reaped;
}
static int fio_ioring_getevents(struct thread_data *td, unsigned int min,
unsigned int max, const struct timespec *t)
{
struct ioring_data *ld = td->io_ops_data;
unsigned actual_min = td->o.iodepth_batch_complete_min == 0 ? 0 : min;
struct ioring_options *o = td->eo;
struct io_cq_ring *ring = &ld->cq_ring;
unsigned events = 0;
int r;
ld->cq_ring_off = *ring->head;
do {
r = fio_ioring_cqring_reap(td, events, max);
if (r) {
events += r;
if (actual_min != 0)
actual_min -= r;
continue;
}
if (!o->sqpoll_thread) {
r = io_uring_enter(ld, 0, actual_min,
IORING_ENTER_GETEVENTS);
if (r < 0) {
if (errno == EAGAIN || errno == EINTR)
continue;
td_verror(td, errno, "io_uring_enter");
break;
}
}
} while (events < min);
return r < 0 ? r : events;
}
static void fio_ioring_prio_prep(struct thread_data *td, struct io_u *io_u)
{
struct ioring_options *o = td->eo;
struct ioring_data *ld = td->io_ops_data;
if (rand_between(&td->prio_state, 0, 99) < o->cmdprio_percentage) {
ld->sqes[io_u->index].ioprio = IOPRIO_CLASS_RT << IOPRIO_CLASS_SHIFT;
io_u->flags |= IO_U_F_PRIORITY;
}
return;
}
static enum fio_q_status fio_ioring_queue(struct thread_data *td,
struct io_u *io_u)
{
struct ioring_data *ld = td->io_ops_data;
struct io_sq_ring *ring = &ld->sq_ring;
struct ioring_options *o = td->eo;
unsigned tail, next_tail;
fio_ro_check(td, io_u);
if (ld->queued == ld->iodepth)
return FIO_Q_BUSY;
if (io_u->ddir == DDIR_TRIM) {
if (ld->queued)
return FIO_Q_BUSY;
do_io_u_trim(td, io_u);
io_u_mark_submit(td, 1);
io_u_mark_complete(td, 1);
return FIO_Q_COMPLETED;
}
tail = *ring->tail;
next_tail = tail + 1;
read_barrier();
if (next_tail == *ring->head)
return FIO_Q_BUSY;
if (o->cmdprio_percentage)
fio_ioring_prio_prep(td, io_u);
ring->array[tail & ld->sq_ring_mask] = io_u->index;
*ring->tail = next_tail;
write_barrier();
ld->queued++;
return FIO_Q_QUEUED;
}
static void fio_ioring_queued(struct thread_data *td, int start, int nr)
{
struct ioring_data *ld = td->io_ops_data;
struct timespec now;
if (!fio_fill_issue_time(td))
return;
fio_gettime(&now, NULL);
while (nr--) {
struct io_sq_ring *ring = &ld->sq_ring;
int index = ring->array[start & ld->sq_ring_mask];
struct io_u *io_u = ld->io_u_index[index];
memcpy(&io_u->issue_time, &now, sizeof(now));
io_u_queued(td, io_u);
start++;
}
}
static int fio_ioring_commit(struct thread_data *td)
{
struct ioring_data *ld = td->io_ops_data;
struct ioring_options *o = td->eo;
int ret;
if (!ld->queued)
return 0;
/*
* Kernel side does submission. just need to check if the ring is
* flagged as needing a kick, if so, call io_uring_enter(). This
* only happens if we've been idle too long.
*/
if (o->sqpoll_thread) {
struct io_sq_ring *ring = &ld->sq_ring;
read_barrier();
if (*ring->flags & IORING_SQ_NEED_WAKEUP)
io_uring_enter(ld, ld->queued, 0,
IORING_ENTER_SQ_WAKEUP);
ld->queued = 0;
return 0;
}
do {
unsigned start = *ld->sq_ring.head;
long nr = ld->queued;
ret = io_uring_enter(ld, nr, 0, IORING_ENTER_GETEVENTS);
if (ret > 0) {
fio_ioring_queued(td, start, ret);
io_u_mark_submit(td, ret);
ld->queued -= ret;
ret = 0;
} else if (!ret) {
io_u_mark_submit(td, ret);
continue;
} else {
if (errno == EAGAIN || errno == EINTR) {
ret = fio_ioring_cqring_reap(td, 0, ld->queued);
if (ret)
continue;
/* Shouldn't happen */
usleep(1);
continue;
}
td_verror(td, errno, "io_uring_enter submit");
break;
}
} while (ld->queued);
return ret;
}
static void fio_ioring_unmap(struct ioring_data *ld)
{
int i;
for (i = 0; i < ARRAY_SIZE(ld->mmap); i++)
munmap(ld->mmap[i].ptr, ld->mmap[i].len);
close(ld->ring_fd);
}
static void fio_ioring_cleanup(struct thread_data *td)
{
struct ioring_data *ld = td->io_ops_data;
if (ld) {
if (!(td->flags & TD_F_CHILD))
fio_ioring_unmap(ld);
free(ld->io_u_index);
free(ld->iovecs);
free(ld->fds);
free(ld);
}
}
static int fio_ioring_mmap(struct ioring_data *ld, struct io_uring_params *p)
{
struct io_sq_ring *sring = &ld->sq_ring;
struct io_cq_ring *cring = &ld->cq_ring;
void *ptr;
ld->mmap[0].len = p->sq_off.array + p->sq_entries * sizeof(__u32);
ptr = mmap(0, ld->mmap[0].len, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_POPULATE, ld->ring_fd,
IORING_OFF_SQ_RING);
ld->mmap[0].ptr = 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;
ld->sq_ring_mask = *sring->ring_mask;
ld->mmap[1].len = p->sq_entries * sizeof(struct io_uring_sqe);
ld->sqes = mmap(0, ld->mmap[1].len, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_POPULATE, ld->ring_fd,
IORING_OFF_SQES);
ld->mmap[1].ptr = ld->sqes;
ld->mmap[2].len = p->cq_off.cqes +
p->cq_entries * sizeof(struct io_uring_cqe);
ptr = mmap(0, ld->mmap[2].len, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_POPULATE, ld->ring_fd,
IORING_OFF_CQ_RING);
ld->mmap[2].ptr = 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;
ld->cq_ring_mask = *cring->ring_mask;
return 0;
}
static int fio_ioring_queue_init(struct thread_data *td)
{
struct ioring_data *ld = td->io_ops_data;
struct ioring_options *o = td->eo;
int depth = td->o.iodepth;
struct io_uring_params p;
int ret;
memset(&p, 0, sizeof(p));
if (o->hipri)
p.flags |= IORING_SETUP_IOPOLL;
if (o->sqpoll_thread) {
p.flags |= IORING_SETUP_SQPOLL;
if (o->sqpoll_set) {
p.flags |= IORING_SETUP_SQ_AFF;
p.sq_thread_cpu = o->sqpoll_cpu;
}
}
ret = syscall(__NR_io_uring_setup, depth, &p);
if (ret < 0)
return ret;
ld->ring_fd = ret;
if (o->fixedbufs) {
struct rlimit rlim = {
.rlim_cur = RLIM_INFINITY,
.rlim_max = RLIM_INFINITY,
};
if (setrlimit(RLIMIT_MEMLOCK, &rlim) < 0)
return -1;
ret = syscall(__NR_io_uring_register, ld->ring_fd,
IORING_REGISTER_BUFFERS, ld->iovecs, depth);
if (ret < 0)
return ret;
}
return fio_ioring_mmap(ld, &p);
}
static int fio_ioring_register_files(struct thread_data *td)
{
struct ioring_data *ld = td->io_ops_data;
struct fio_file *f;
unsigned int i;
int ret;
ld->fds = calloc(td->o.nr_files, sizeof(int));
for_each_file(td, f, i) {
ret = generic_open_file(td, f);
if (ret)
goto err;
ld->fds[i] = f->fd;
f->engine_pos = i;
}
ret = syscall(__NR_io_uring_register, ld->ring_fd,
IORING_REGISTER_FILES, ld->fds, td->o.nr_files);
if (ret) {
err:
free(ld->fds);
ld->fds = NULL;
}
/*
* Pretend the file is closed again, and really close it if we hit
* an error.
*/
for_each_file(td, f, i) {
if (ret) {
int fio_unused ret2;
ret2 = generic_close_file(td, f);
} else
f->fd = -1;
}
return ret;
}
static int fio_ioring_post_init(struct thread_data *td)
{
struct ioring_data *ld = td->io_ops_data;
struct ioring_options *o = td->eo;
struct io_u *io_u;
int err, i;
for (i = 0; i < td->o.iodepth; i++) {
struct iovec *iov = &ld->iovecs[i];
io_u = ld->io_u_index[i];
iov->iov_base = io_u->buf;
iov->iov_len = td_max_bs(td);
}
err = fio_ioring_queue_init(td);
if (err) {
td_verror(td, errno, "io_queue_init");
return 1;
}
if (o->registerfiles) {
err = fio_ioring_register_files(td);
if (err) {
td_verror(td, errno, "ioring_register_files");
return 1;
}
}
return 0;
}
static unsigned roundup_pow2(unsigned depth)
{
return 1UL << __fls(depth - 1);
}
static int fio_ioring_init(struct thread_data *td)
{
struct ioring_options *o = td->eo;
struct ioring_data *ld;
struct thread_options *to = &td->o;
/* sqthread submission requires registered files */
if (o->sqpoll_thread)
o->registerfiles = 1;
if (o->registerfiles && td->o.nr_files != td->o.open_files) {
log_err("fio: io_uring registered files require nr_files to "
"be identical to open_files\n");
return 1;
}
ld = calloc(1, sizeof(*ld));
/* ring depth must be a power-of-2 */
ld->iodepth = td->o.iodepth;
td->o.iodepth = roundup_pow2(td->o.iodepth);
/* io_u index */
ld->io_u_index = calloc(td->o.iodepth, sizeof(struct io_u *));
ld->iovecs = calloc(td->o.iodepth, sizeof(struct iovec));
td->io_ops_data = ld;
/*
* Check for option conflicts
*/
if ((fio_option_is_set(to, ioprio) || fio_option_is_set(to, ioprio_class)) &&
o->cmdprio_percentage != 0) {
log_err("%s: cmdprio_percentage option and mutually exclusive "
"prio or prioclass option is set, exiting\n", to->name);
td_verror(td, EINVAL, "fio_io_uring_init");
return 1;
}
if (fio_option_is_set(&td->o, ioprio_class))
ld->ioprio_class_set = true;
if (fio_option_is_set(&td->o, ioprio))
ld->ioprio_set = true;
return 0;
}
static int fio_ioring_io_u_init(struct thread_data *td, struct io_u *io_u)
{
struct ioring_data *ld = td->io_ops_data;
ld->io_u_index[io_u->index] = io_u;
return 0;
}
static int fio_ioring_open_file(struct thread_data *td, struct fio_file *f)
{
struct ioring_data *ld = td->io_ops_data;
struct ioring_options *o = td->eo;
if (!ld || !o->registerfiles)
return generic_open_file(td, f);
f->fd = ld->fds[f->engine_pos];
return 0;
}
static int fio_ioring_close_file(struct thread_data *td, struct fio_file *f)
{
struct ioring_data *ld = td->io_ops_data;
struct ioring_options *o = td->eo;
if (!ld || !o->registerfiles)
return generic_close_file(td, f);
f->fd = -1;
return 0;
}
static struct ioengine_ops ioengine = {
.name = "io_uring",
.version = FIO_IOOPS_VERSION,
.flags = FIO_ASYNCIO_SYNC_TRIM,
.init = fio_ioring_init,
.post_init = fio_ioring_post_init,
.io_u_init = fio_ioring_io_u_init,
.prep = fio_ioring_prep,
.queue = fio_ioring_queue,
.commit = fio_ioring_commit,
.getevents = fio_ioring_getevents,
.event = fio_ioring_event,
.cleanup = fio_ioring_cleanup,
.open_file = fio_ioring_open_file,
.close_file = fio_ioring_close_file,
.get_file_size = generic_get_file_size,
.options = options,
.option_struct_size = sizeof(struct ioring_options),
};
static void fio_init fio_ioring_register(void)
{
register_ioengine(&ioengine);
}
static void fio_exit fio_ioring_unregister(void)
{
unregister_ioengine(&ioengine);
}
#endif