+/*
+ * aioring engine
+ *
+ * IO engine using the new native Linux libaio ring interface
+ *
+ */
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <libaio.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+
+#include "../fio.h"
+#include "../lib/pow2.h"
+#include "../optgroup.h"
+#include "../lib/memalign.h"
+
+#ifndef IOCB_FLAG_HIPRI
+#define IOCB_FLAG_HIPRI (1 << 2)
+#endif
+
+/*
+ * io_setup2(2) flags
+ */
+#ifndef IOCTX_FLAG_IOPOLL
+#define IOCTX_FLAG_IOPOLL (1 << 0)
+#endif
+#ifndef IOCTX_FLAG_SCQRING
+#define IOCTX_FLAG_SCQRING (1 << 1)
+#endif
+#ifndef IOCTX_FLAG_FIXEDBUFS
+#define IOCTX_FLAG_FIXEDBUFS (1 << 2)
+#endif
+#ifndef IOCTX_FLAG_SQTHREAD
+#define IOCTX_FLAG_SQTHREAD (1 << 3)
+#endif
+#ifndef IOCTX_FLAG_SQWQ
+#define IOCTX_FLAG_SQWQ (1 << 4)
+#endif
+
+/*
+ * io_ring_enter(2) flags
+ */
+#ifndef IORING_FLAG_SUBMIT
+#define IORING_FLAG_SUBMIT (1 << 0)
+#endif
+#ifndef IORING_FLAG_GETEVENTS
+#define IORING_FLAG_GETEVENTS (1 << 1)
+#endif
+
+typedef uint64_t u64;
+typedef uint32_t u32;
+typedef uint16_t u16;
+
+struct aio_sq_ring {
+ union {
+ struct {
+ u32 head;
+ u32 tail;
+ u32 nr_events;
+ u16 sq_thread_cpu;
+ u64 iocbs;
+ };
+ u32 pad[16];
+ };
+ u32 array[0];
+};
+
+struct aio_cq_ring {
+ union {
+ struct {
+ u32 head;
+ u32 tail;
+ u32 nr_events;
+ };
+ struct io_event pad;
+ };
+ struct io_event events[0];
+};
+
+struct aioring_data {
+ io_context_t aio_ctx;
+ struct io_u **io_us;
+ struct io_u **io_u_index;
+
+ struct aio_sq_ring *sq_ring;
+ struct iocb *iocbs;
+
+ struct aio_cq_ring *cq_ring;
+ struct io_event *events;
+
+ int queued;
+ int cq_ring_off;
+};
+
+struct aioring_options {
+ void *pad;
+ unsigned int hipri;
+ unsigned int fixedbufs;
+};
+
+static struct fio_option options[] = {
+ {
+ .name = "hipri",
+ .lname = "High Priority",
+ .type = FIO_OPT_STR_SET,
+ .off1 = offsetof(struct aioring_options, hipri),
+ .help = "Use polled IO completions",
+ .category = FIO_OPT_C_ENGINE,
+ .group = FIO_OPT_G_LIBAIO,
+ },
+ {
+ .name = "fixedbufs",
+ .lname = "Fixed (pre-mapped) IO buffers",
+ .type = FIO_OPT_STR_SET,
+ .off1 = offsetof(struct aioring_options, fixedbufs),
+ .help = "Pre map IO buffers",
+ .category = FIO_OPT_C_ENGINE,
+ .group = FIO_OPT_G_LIBAIO,
+ },
+ {
+ .name = NULL,
+ },
+};
+
+static int fio_aioring_commit(struct thread_data *td);
+
+static int io_ring_enter(io_context_t ctx, unsigned int to_submit,
+ unsigned int min_complete, unsigned int flags)
+{
+#ifdef __NR_sys_io_ring_enter
+ return syscall(__NR_sys_io_ring_enter, ctx, to_submit, min_complete,
+ flags);
+#else
+ return -1;
+#endif
+}
+
+static int fio_aioring_prep(struct thread_data *td, struct io_u *io_u)
+{
+ struct aioring_data *ld = td->io_ops_data;
+ struct fio_file *f = io_u->file;
+ struct aioring_options *o = td->eo;
+ struct iocb *iocb;
+
+ iocb = &ld->iocbs[io_u->index];
+
+ if (io_u->ddir == DDIR_READ) {
+ if (o->fixedbufs) {
+ iocb->aio_fildes = f->fd;
+ iocb->aio_lio_opcode = IO_CMD_PREAD;
+ iocb->u.c.offset = io_u->offset;
+ } else {
+ io_prep_pread(iocb, f->fd, io_u->xfer_buf, io_u->xfer_buflen, io_u->offset);
+ if (o->hipri)
+ iocb->u.c.flags |= IOCB_FLAG_HIPRI;
+ }
+ } else if (io_u->ddir == DDIR_WRITE) {
+ if (o->fixedbufs) {
+ iocb->aio_fildes = f->fd;
+ iocb->aio_lio_opcode = IO_CMD_PWRITE;
+ iocb->u.c.offset = io_u->offset;
+ } else {
+ io_prep_pwrite(iocb, f->fd, io_u->xfer_buf, io_u->xfer_buflen, io_u->offset);
+ if (o->hipri)
+ iocb->u.c.flags |= IOCB_FLAG_HIPRI;
+ }
+ } else if (ddir_sync(io_u->ddir))
+ io_prep_fsync(iocb, f->fd);
+
+ iocb->data = io_u;
+ return 0;
+}
+
+static struct io_u *fio_aioring_event(struct thread_data *td, int event)
+{
+ struct aioring_data *ld = td->io_ops_data;
+ struct io_event *ev;
+ struct io_u *io_u;
+ int index;
+
+ index = event + ld->cq_ring_off;
+ if (index >= ld->cq_ring->nr_events)
+ index -= ld->cq_ring->nr_events;
+
+ ev = &ld->cq_ring->events[index];
+ io_u = ev->data;
+
+ if (ev->res != io_u->xfer_buflen) {
+ if (ev->res > io_u->xfer_buflen)
+ io_u->error = -ev->res;
+ else
+ io_u->resid = io_u->xfer_buflen - ev->res;
+ } else
+ io_u->error = 0;
+
+ return io_u;
+}
+
+static int fio_aioring_cqring_reap(struct thread_data *td, unsigned int events,
+ unsigned int max)
+{
+ struct aioring_data *ld = td->io_ops_data;
+ struct aio_cq_ring *ring = ld->cq_ring;
+ u32 head, reaped = 0;
+
+ head = ring->head;
+ do {
+ read_barrier();
+ if (head == ring->tail)
+ break;
+ reaped++;
+ head++;
+ if (head == ring->nr_events)
+ head = 0;
+ } while (reaped + events < max);
+
+ ring->head = head;
+ write_barrier();
+ return reaped;
+}
+
+static int fio_aioring_getevents(struct thread_data *td, unsigned int min,
+ unsigned int max, const struct timespec *t)
+{
+ struct aioring_data *ld = td->io_ops_data;
+ unsigned actual_min = td->o.iodepth_batch_complete_min == 0 ? 0 : min;
+ struct aio_cq_ring *ring = ld->cq_ring;
+ int r, events = 0;
+
+ ld->cq_ring_off = ring->head;
+ do {
+ r = fio_aioring_cqring_reap(td, events, max);
+ if (r) {
+ events += r;
+ continue;
+ }
+
+ r = io_ring_enter(ld->aio_ctx, 0, actual_min,
+ IORING_FLAG_GETEVENTS);
+ if (r < 0) {
+ if (errno == EAGAIN)
+ continue;
+ perror("ring enter");
+ break;
+ }
+ } while (events < min);
+
+ return r < 0 ? r : events;
+}
+
+static enum fio_q_status fio_aioring_queue(struct thread_data *td,
+ struct io_u *io_u)
+{
+ struct aioring_data *ld = td->io_ops_data;
+ struct aio_sq_ring *ring = ld->sq_ring;
+ unsigned tail, next_tail;
+
+ fio_ro_check(td, io_u);
+
+ if (ld->queued == td->o.iodepth)
+ return FIO_Q_BUSY;
+
+ /*
+ * fsync is tricky, since it can fail and we need to do it
+ * serialized with other io. the reason is that linux doesn't
+ * support aio fsync yet. So return busy for the case where we
+ * have pending io, to let fio complete those first.
+ */
+ if (ddir_sync(io_u->ddir)) {
+ if (ld->queued)
+ return FIO_Q_BUSY;
+
+ do_io_u_sync(td, io_u);
+ return FIO_Q_COMPLETED;
+ }
+
+ 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;
+ if (next_tail == ring->nr_events)
+ next_tail = 0;
+ read_barrier();
+ if (next_tail == ring->head)
+ return FIO_Q_BUSY;
+
+ ring->array[tail] = io_u->index;
+ ring->tail = next_tail;
+ write_barrier();
+
+ ld->queued++;
+ return FIO_Q_QUEUED;
+}
+
+static void fio_aioring_queued(struct thread_data *td, int start, int nr)
+{
+ struct aioring_data *ld = td->io_ops_data;
+ struct timespec now;
+
+ if (!fio_fill_issue_time(td))
+ return;
+
+ fio_gettime(&now, NULL);
+
+ while (nr--) {
+ int index = ld->sq_ring->array[start];
+ struct io_u *io_u = io_u = ld->io_u_index[index];
+
+ memcpy(&io_u->issue_time, &now, sizeof(now));
+ io_u_queued(td, io_u);
+
+ start++;
+ if (start == ld->sq_ring->nr_events)
+ start = 0;
+ }
+}
+
+static int fio_aioring_commit(struct thread_data *td)
+{
+ struct aioring_data *ld = td->io_ops_data;
+ int ret;
+
+ if (!ld->queued)
+ return 0;
+
+ do {
+ int start = ld->sq_ring->head;
+ long nr = ld->queued;
+
+ ret = io_ring_enter(ld->aio_ctx, nr, 0, IORING_FLAG_SUBMIT |
+ IORING_FLAG_GETEVENTS);
+ if (ret == -1)
+ perror("io_ring_enter");
+ if (ret > 0) {
+ fio_aioring_queued(td, start, ret);
+ io_u_mark_submit(td, ret);
+
+ ld->queued -= ret;
+ ret = 0;
+ } else if (ret == -EINTR || !ret) {
+ if (!ret)
+ io_u_mark_submit(td, ret);
+ continue;
+ } else if (ret == -EAGAIN) {
+ /*
+ * If we get EAGAIN, we should break out without
+ * error and let the upper layer reap some
+ * events for us. If we have no queued IO, we
+ * must loop here. If we loop for more than 30s,
+ * just error out, something must be buggy in the
+ * IO path.
+ */
+ if (ld->queued) {
+ ret = 0;
+ break;
+ }
+ usleep(1);
+ continue;
+ } else if (ret == -ENOMEM) {
+ /*
+ * If we get -ENOMEM, reap events if we can. If
+ * we cannot, treat it as a fatal event since there's
+ * nothing we can do about it.
+ */
+ if (ld->queued)
+ ret = 0;
+ break;
+ } else
+ break;
+ } while (ld->queued);
+
+ return ret;
+}
+
+static size_t aioring_cq_size(struct thread_data *td)
+{
+ return sizeof(struct aio_cq_ring) + 2 * td->o.iodepth * sizeof(struct io_event);
+}
+
+static size_t aioring_sq_iocb(struct thread_data *td)
+{
+ return sizeof(struct iocb) * td->o.iodepth;
+}
+
+static size_t aioring_sq_size(struct thread_data *td)
+{
+ return sizeof(struct aio_sq_ring) + td->o.iodepth * sizeof(u32);
+}
+
+static void fio_aioring_cleanup(struct thread_data *td)
+{
+ struct aioring_data *ld = td->io_ops_data;
+
+ if (ld) {
+ /*
+ * Work-around to avoid huge RCU stalls at exit time. If we
+ * don't do this here, then it'll be torn down by exit_aio().
+ * But for that case we can parallellize the freeing, thus
+ * speeding it up a lot.
+ */
+ if (!(td->flags & TD_F_CHILD))
+ io_destroy(ld->aio_ctx);
+ free(ld->io_u_index);
+ free(ld->io_us);
+ fio_memfree(ld->sq_ring, aioring_sq_size(td), false);
+ fio_memfree(ld->iocbs, aioring_sq_iocb(td), false);
+ fio_memfree(ld->cq_ring, aioring_cq_size(td), false);
+ free(ld);
+ }
+}
+
+static int fio_aioring_queue_init(struct thread_data *td)
+{
+#ifdef __NR_sys_io_setup2
+ struct aioring_data *ld = td->io_ops_data;
+ struct aioring_options *o = td->eo;
+ int flags = IOCTX_FLAG_SCQRING;
+ int depth = td->o.iodepth;
+
+ if (o->hipri)
+ flags |= IOCTX_FLAG_IOPOLL;
+ if (o->fixedbufs) {
+ struct rlimit rlim = {
+ .rlim_cur = RLIM_INFINITY,
+ .rlim_max = RLIM_INFINITY,
+ };
+
+ setrlimit(RLIMIT_MEMLOCK, &rlim);
+ flags |= IOCTX_FLAG_FIXEDBUFS;
+ }
+
+ return syscall(__NR_sys_io_setup2, depth, flags,
+ ld->sq_ring, ld->cq_ring, &ld->aio_ctx);
+#else
+ return -1;
+#endif
+}
+
+static int fio_aioring_post_init(struct thread_data *td)
+{
+ struct aioring_data *ld = td->io_ops_data;
+ struct aioring_options *o = td->eo;
+ struct io_u *io_u;
+ struct iocb *iocb;
+ int err = 0;
+
+ if (o->fixedbufs) {
+ int i;
+
+ for (i = 0; i < td->o.iodepth; i++) {
+ io_u = ld->io_u_index[i];
+ iocb = &ld->iocbs[i];
+ iocb->u.c.buf = io_u->buf;
+ iocb->u.c.nbytes = td_max_bs(td);
+
+ if (o->hipri)
+ iocb->u.c.flags |= IOCB_FLAG_HIPRI;
+ }
+ }
+
+ err = fio_aioring_queue_init(td);
+ if (err) {
+ td_verror(td, -err, "io_queue_init");
+ return 1;
+ }
+
+ return 0;
+}
+
+static int fio_aioring_init(struct thread_data *td)
+{
+ struct aioring_data *ld;
+
+ if (td->o.iodepth <= 1) {
+ printf("aio-ring: needs a minimum QD of 2\n");
+ return 1;
+ }
+
+ ld = calloc(1, sizeof(*ld));
+
+ /* io_u index */
+ ld->io_u_index = calloc(td->o.iodepth, sizeof(struct io_u *));
+ ld->io_us = calloc(td->o.iodepth, sizeof(struct io_u *));
+
+ ld->iocbs = fio_memalign(page_size, aioring_sq_iocb(td), false);
+ memset(ld->iocbs, 0, aioring_sq_iocb(td));
+
+ ld->sq_ring = fio_memalign(page_size, aioring_sq_size(td), false);
+ memset(ld->sq_ring, 0, aioring_sq_size(td));
+ ld->sq_ring->nr_events = td->o.iodepth;
+ ld->sq_ring->iocbs = (u64) ld->iocbs;
+
+ ld->cq_ring = fio_memalign(page_size, aioring_cq_size(td), false);
+ memset(ld->cq_ring, 0, aioring_cq_size(td));
+ ld->cq_ring->nr_events = td->o.iodepth * 2;
+
+ td->io_ops_data = ld;
+ return 0;
+}
+
+static int fio_aioring_io_u_init(struct thread_data *td, struct io_u *io_u)
+{
+ struct aioring_data *ld = td->io_ops_data;
+
+ ld->io_u_index[io_u->index] = io_u;
+ return 0;
+}
+
+static struct ioengine_ops ioengine = {
+ .name = "aio-ring",
+ .version = FIO_IOOPS_VERSION,
+ .init = fio_aioring_init,
+ .post_init = fio_aioring_post_init,
+ .io_u_init = fio_aioring_io_u_init,
+ .prep = fio_aioring_prep,
+ .queue = fio_aioring_queue,
+ .commit = fio_aioring_commit,
+ .getevents = fio_aioring_getevents,
+ .event = fio_aioring_event,
+ .cleanup = fio_aioring_cleanup,
+ .open_file = generic_open_file,
+ .close_file = generic_close_file,
+ .get_file_size = generic_get_file_size,
+ .options = options,
+ .option_struct_size = sizeof(struct aioring_options),
+};
+
+static void fio_init fio_aioring_register(void)
+{
+#ifdef __NR_sys_io_setup2
+#ifdef __NR_sys_io_ring_enter
+ register_ioengine(&ioengine);
+#endif
+#endif
+}
+
+static void fio_exit fio_aioring_unregister(void)
+{
+#ifdef __NR_sys_io_setup2
+#ifdef __NR_sys_io_ring_enter
+ unregister_ioengine(&ioengine);
+#endif
+#endif
+}
projects / fio.git / commitdiff