X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=engines%2Flibaio.c;h=d11a262e62cbaf8b0c30bf47e52b9dfaa584ae86;hp=44b7dfa7eb20f811b8d91af67711925c8381a289;hb=8e47b0ad5ba0f567c6ae4fabeb516bc1b4fcd651;hpb=a5f3027cb0495dfe217b2626d248fcc054e7e878 diff --git a/engines/libaio.c b/engines/libaio.c index 44b7dfa7..d11a262e 100644 --- a/engines/libaio.c +++ b/engines/libaio.c @@ -9,21 +9,60 @@ #include #include #include +#include #include "../fio.h" -#ifdef FIO_HAVE_LIBAIO - -#define ev_to_iou(ev) (struct io_u *) ((unsigned long) (ev)->obj) - struct libaio_data { io_context_t aio_ctx; struct io_event *aio_events; struct iocb **iocbs; struct io_u **io_us; - int iocbs_nr; + + /* + * 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 { + struct thread_data *td; + 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; @@ -34,8 +73,6 @@ static int fio_libaio_prep(struct thread_data fio_unused *td, struct io_u *io_u) 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); - else - return 1; return 0; } @@ -47,7 +84,7 @@ static struct io_u *fio_libaio_event(struct thread_data *td, int event) struct io_u *io_u; ev = ld->aio_events + event; - io_u = ev_to_iou(ev); + io_u = container_of(ev->obj, struct io_u, iocb); if (ev->res != io_u->xfer_buflen) { if (ev->res > io_u->xfer_buflen) @@ -60,26 +97,81 @@ static struct io_u *fio_libaio_event(struct thread_data *td, int event) 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, struct timespec *t) + unsigned int max, const struct timespec *t) { struct libaio_data *ld = td->io_ops->data; - int r; + 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 { - r = io_getevents(ld->aio_ctx, min, max, ld->aio_events, t); - if (r >= (int) min) - break; - else if (r == -EAGAIN) { + 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 (r == -EAGAIN) usleep(100); - continue; - } else if (r == -EINTR) - continue; - else if (r != 0) + else if (r != -EINTR) break; - } while (1); + } while (events < min); - return r; + return r < 0 ? r : events; } static int fio_libaio_queue(struct thread_data *td, struct io_u *io_u) @@ -88,7 +180,7 @@ static int fio_libaio_queue(struct thread_data *td, struct io_u *io_u) fio_ro_check(td, io_u); - if (ld->iocbs_nr == (int) td->o.iodepth) + if (ld->queued == td->o.iodepth) return FIO_Q_BUSY; /* @@ -98,7 +190,7 @@ static int fio_libaio_queue(struct thread_data *td, struct io_u *io_u) * have pending io, to let fio complete those first. */ if (ddir_sync(io_u->ddir)) { - if (ld->iocbs_nr) + if (ld->queued) return FIO_Q_BUSY; do_io_u_sync(td, io_u); @@ -106,16 +198,17 @@ static int fio_libaio_queue(struct thread_data *td, struct io_u *io_u) } if (io_u->ddir == DDIR_TRIM) { - if (ld->iocbs_nr) + if (ld->queued) return FIO_Q_BUSY; do_io_u_trim(td, io_u); return FIO_Q_COMPLETED; } - ld->iocbs[ld->iocbs_nr] = &io_u->iocb; - ld->io_us[ld->iocbs_nr] = io_u; - ld->iocbs_nr++; + 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; } @@ -143,29 +236,67 @@ 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; - int ret; + struct timeval tv; + int ret, wait_start = 0; - if (!ld->iocbs_nr) + if (!ld->queued) return 0; - io_us = ld->io_us; - iocbs = ld->iocbs; do { - ret = io_submit(ld->aio_ctx, ld->iocbs_nr, iocbs); + 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->iocbs_nr -= ret; - io_us += ret; - iocbs += ret; + + ld->queued -= ret; + ring_inc(ld, &ld->tail, ret); ret = 0; - } else if (!ret || ret == -EAGAIN || ret == -EINTR) { + 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 = 0; + } 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->iocbs_nr); + } while (ld->queued); return ret; } @@ -192,12 +323,21 @@ static void fio_libaio_cleanup(struct thread_data *td) static int fio_libaio_init(struct thread_data *td) { - struct libaio_data *ld = malloc(sizeof(*ld)); - int err; + struct libaio_options *o = td->eo; + struct libaio_data *ld; + int err = 0; - memset(ld, 0, sizeof(*ld)); + ld = calloc(1, sizeof(*ld)); - err = io_queue_init(td->o.iodepth, &ld->aio_ctx); + /* + * 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"); @@ -205,55 +345,34 @@ static int fio_libaio_init(struct thread_data *td) return 1; } - ld->aio_events = malloc(td->o.iodepth * sizeof(struct io_event)); - memset(ld->aio_events, 0, td->o.iodepth * sizeof(struct io_event)); - ld->iocbs = malloc(td->o.iodepth * sizeof(struct iocb *)); - memset(ld->iocbs, 0, sizeof(struct iocb *)); - ld->io_us = malloc(td->o.iodepth * sizeof(struct io_u *)); - memset(ld->io_us, 0, td->o.iodepth * sizeof(struct io_u *)); - ld->iocbs_nr = 0; + 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, -}; - -#else /* FIO_HAVE_LIBAIO */ - -/* - * When we have a proper configure system in place, we simply wont build - * and install this io engine. For now install a crippled version that - * just complains and fails to load. - */ -static int fio_libaio_init(struct thread_data fio_unused *td) -{ - fprintf(stderr, "fio: libaio not available\n"); - return 1; -} - -static struct ioengine_ops ioengine = { - .name = "libaio", - .version = FIO_IOOPS_VERSION, - .init = fio_libaio_init, + .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), }; -#endif - static void fio_init fio_libaio_register(void) { register_ioengine(&ioengine);