| /* |
| * libaio engine |
| * |
| * IO engine using the Linux native aio interface. |
| * |
| */ |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <errno.h> |
| #include <assert.h> |
| #include <libaio.h> |
| |
| #include "../fio.h" |
| |
| static int fio_libaio_commit(struct thread_data *td); |
| |
| struct libaio_data { |
| io_context_t aio_ctx; |
| struct io_event *aio_events; |
| struct iocb **iocbs; |
| struct io_u **io_us; |
| |
| /* |
| * Basic ring buffer. 'head' is incremented in _queue(), and |
| * 'tail' is incremented in _commit(). We keep 'queued' so |
| * that we know if the ring is full or empty, when |
| * 'head' == 'tail'. 'entries' is the ring size, and |
| * 'is_pow2' is just an optimization to use AND instead of |
| * modulus to get the remainder on ring increment. |
| */ |
| int is_pow2; |
| unsigned int entries; |
| unsigned int queued; |
| unsigned int head; |
| unsigned int tail; |
| }; |
| |
| struct libaio_options { |
| void *pad; |
| unsigned int userspace_reap; |
| }; |
| |
| static struct fio_option options[] = { |
| { |
| .name = "userspace_reap", |
| .lname = "Libaio userspace reaping", |
| .type = FIO_OPT_STR_SET, |
| .off1 = offsetof(struct libaio_options, userspace_reap), |
| .help = "Use alternative user-space reap implementation", |
| .category = FIO_OPT_C_ENGINE, |
| .group = FIO_OPT_G_LIBAIO, |
| }, |
| { |
| .name = NULL, |
| }, |
| }; |
| |
| static inline void ring_inc(struct libaio_data *ld, unsigned int *val, |
| unsigned int add) |
| { |
| if (ld->is_pow2) |
| *val = (*val + add) & (ld->entries - 1); |
| else |
| *val = (*val + add) % ld->entries; |
| } |
| |
| static int fio_libaio_prep(struct thread_data fio_unused *td, struct io_u *io_u) |
| { |
| struct fio_file *f = io_u->file; |
| |
| if (io_u->ddir == DDIR_READ) |
| io_prep_pread(&io_u->iocb, f->fd, io_u->xfer_buf, io_u->xfer_buflen, io_u->offset); |
| else if (io_u->ddir == DDIR_WRITE) |
| io_prep_pwrite(&io_u->iocb, f->fd, io_u->xfer_buf, io_u->xfer_buflen, io_u->offset); |
| else if (ddir_sync(io_u->ddir)) |
| io_prep_fsync(&io_u->iocb, f->fd); |
| |
| return 0; |
| } |
| |
| static struct io_u *fio_libaio_event(struct thread_data *td, int event) |
| { |
| struct libaio_data *ld = td->io_ops->data; |
| struct io_event *ev; |
| struct io_u *io_u; |
| |
| ev = ld->aio_events + event; |
| io_u = container_of(ev->obj, struct io_u, iocb); |
| |
| 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; |
| } |
| |
| struct aio_ring { |
| unsigned id; /** kernel internal index number */ |
| unsigned nr; /** number of io_events */ |
| unsigned head; |
| unsigned tail; |
| |
| unsigned magic; |
| unsigned compat_features; |
| unsigned incompat_features; |
| unsigned header_length; /** size of aio_ring */ |
| |
| struct io_event events[0]; |
| }; |
| |
| #define AIO_RING_MAGIC 0xa10a10a1 |
| |
| static int user_io_getevents(io_context_t aio_ctx, unsigned int max, |
| struct io_event *events) |
| { |
| long i = 0; |
| unsigned head; |
| struct aio_ring *ring = (struct aio_ring*) aio_ctx; |
| |
| while (i < max) { |
| head = ring->head; |
| |
| if (head == ring->tail) { |
| /* There are no more completions */ |
| break; |
| } else { |
| /* There is another completion to reap */ |
| events[i] = ring->events[head]; |
| read_barrier(); |
| ring->head = (head + 1) % ring->nr; |
| i++; |
| } |
| } |
| |
| return i; |
| } |
| |
| static int fio_libaio_getevents(struct thread_data *td, unsigned int min, |
| unsigned int max, const struct timespec *t) |
| { |
| struct libaio_data *ld = td->io_ops->data; |
| struct libaio_options *o = td->eo; |
| unsigned actual_min = td->o.iodepth_batch_complete == 0 ? 0 : min; |
| struct timespec __lt, *lt = NULL; |
| int r, events = 0; |
| |
| if (t) { |
| __lt = *t; |
| lt = &__lt; |
| } |
| |
| do { |
| if (o->userspace_reap == 1 |
| && actual_min == 0 |
| && ((struct aio_ring *)(ld->aio_ctx))->magic |
| == AIO_RING_MAGIC) { |
| r = user_io_getevents(ld->aio_ctx, max, |
| ld->aio_events + events); |
| } else { |
| r = io_getevents(ld->aio_ctx, actual_min, |
| max, ld->aio_events + events, lt); |
| } |
| if (r > 0) |
| events += r; |
| else if ((min && r == 0) || r == -EAGAIN) { |
| fio_libaio_commit(td); |
| usleep(100); |
| } else if (r != -EINTR) |
| break; |
| } while (events < min); |
| |
| return r < 0 ? r : events; |
| } |
| |
| static int fio_libaio_queue(struct thread_data *td, struct io_u *io_u) |
| { |
| struct libaio_data *ld = td->io_ops->data; |
| |
| 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); |
| return FIO_Q_COMPLETED; |
| } |
| |
| ld->iocbs[ld->head] = &io_u->iocb; |
| ld->io_us[ld->head] = io_u; |
| ring_inc(ld, &ld->head, 1); |
| ld->queued++; |
| return FIO_Q_QUEUED; |
| } |
| |
| static void fio_libaio_queued(struct thread_data *td, struct io_u **io_us, |
| unsigned int nr) |
| { |
| struct timeval now; |
| unsigned int i; |
| |
| if (!fio_fill_issue_time(td)) |
| return; |
| |
| fio_gettime(&now, NULL); |
| |
| for (i = 0; i < nr; i++) { |
| struct io_u *io_u = io_us[i]; |
| |
| memcpy(&io_u->issue_time, &now, sizeof(now)); |
| io_u_queued(td, io_u); |
| } |
| } |
| |
| static int fio_libaio_commit(struct thread_data *td) |
| { |
| struct libaio_data *ld = td->io_ops->data; |
| struct iocb **iocbs; |
| struct io_u **io_us; |
| struct timeval tv; |
| int ret, wait_start = 0; |
| |
| if (!ld->queued) |
| return 0; |
| |
| do { |
| long nr = ld->queued; |
| |
| nr = min((unsigned int) nr, ld->entries - ld->tail); |
| io_us = ld->io_us + ld->tail; |
| iocbs = ld->iocbs + ld->tail; |
| |
| ret = io_submit(ld->aio_ctx, nr, iocbs); |
| if (ret > 0) { |
| fio_libaio_queued(td, io_us, ret); |
| io_u_mark_submit(td, ret); |
| |
| ld->queued -= ret; |
| ring_inc(ld, &ld->tail, ret); |
| ret = 0; |
| wait_start = 0; |
| } else if (ret == -EINTR || !ret) { |
| if (!ret) |
| io_u_mark_submit(td, ret); |
| wait_start = 0; |
| 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; |
| } |
| if (!wait_start) { |
| fio_gettime(&tv, NULL); |
| wait_start = 1; |
| } else if (mtime_since_now(&tv) > 30000) { |
| log_err("fio: aio appears to be stalled, giving up\n"); |
| 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 int fio_libaio_cancel(struct thread_data *td, struct io_u *io_u) |
| { |
| struct libaio_data *ld = td->io_ops->data; |
| |
| return io_cancel(ld->aio_ctx, &io_u->iocb, ld->aio_events); |
| } |
| |
| static void fio_libaio_cleanup(struct thread_data *td) |
| { |
| struct libaio_data *ld = td->io_ops->data; |
| |
| if (ld) { |
| io_destroy(ld->aio_ctx); |
| free(ld->aio_events); |
| free(ld->iocbs); |
| free(ld->io_us); |
| free(ld); |
| } |
| } |
| |
| static int fio_libaio_init(struct thread_data *td) |
| { |
| struct libaio_options *o = td->eo; |
| struct libaio_data *ld; |
| int err = 0; |
| |
| ld = calloc(1, sizeof(*ld)); |
| |
| /* |
| * First try passing in 0 for queue depth, since we don't |
| * care about the user ring. If that fails, the kernel is too old |
| * and we need the right depth. |
| */ |
| if (!o->userspace_reap) |
| err = io_queue_init(INT_MAX, &ld->aio_ctx); |
| if (o->userspace_reap || err == -EINVAL) |
| err = io_queue_init(td->o.iodepth, &ld->aio_ctx); |
| if (err) { |
| td_verror(td, -err, "io_queue_init"); |
| log_err("fio: check /proc/sys/fs/aio-max-nr\n"); |
| free(ld); |
| return 1; |
| } |
| |
| ld->entries = td->o.iodepth; |
| ld->is_pow2 = is_power_of_2(ld->entries); |
| ld->aio_events = calloc(ld->entries, sizeof(struct io_event)); |
| ld->iocbs = calloc(ld->entries, sizeof(struct iocb *)); |
| ld->io_us = calloc(ld->entries, sizeof(struct io_u *)); |
| |
| td->io_ops->data = ld; |
| return 0; |
| } |
| |
| static struct ioengine_ops ioengine = { |
| .name = "libaio", |
| .version = FIO_IOOPS_VERSION, |
| .init = fio_libaio_init, |
| .prep = fio_libaio_prep, |
| .queue = fio_libaio_queue, |
| .commit = fio_libaio_commit, |
| .cancel = fio_libaio_cancel, |
| .getevents = fio_libaio_getevents, |
| .event = fio_libaio_event, |
| .cleanup = fio_libaio_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 libaio_options), |
| }; |
| |
| static void fio_init fio_libaio_register(void) |
| { |
| register_ioengine(&ioengine); |
| } |
| |
| static void fio_exit fio_libaio_unregister(void) |
| { |
| unregister_ioengine(&ioengine); |
| } |