Because we will support AioContext wide IO submission as batch, so IO resources should be allocated according to how many there are backends in the same AioContext.
Signed-off-by: Ming Lei <ming....@canonical.com> --- block/linux-aio.c | 38 +++++++++++++++++++++++++++++++------- 1 file changed, 31 insertions(+), 7 deletions(-) diff --git a/block/linux-aio.c b/block/linux-aio.c index e3e0532..e219b80 100644 --- a/block/linux-aio.c +++ b/block/linux-aio.c @@ -43,7 +43,7 @@ struct qemu_laiocb { * so in future the IO queue should be per AIO context. */ typedef struct { - struct iocb *iocbs[MAX_QUEUED_IO]; + struct iocb **iocbs; int plugged; unsigned int size; unsigned int idx; @@ -66,6 +66,7 @@ struct qemu_laio_state { LaioQueue *io_q; /* I/O completion processing */ + int nr_evt; QEMUBH *completion_bh; struct io_event *events; int event_idx; @@ -73,6 +74,7 @@ struct qemu_laio_state { /* All BS in the list shared this 'qemu_laio_state' */ QLIST_HEAD(, LaioTrackedBs) tracked_bs; + int nr_bs; AioContext *aio_context; }; @@ -131,7 +133,7 @@ static void qemu_laio_completion_bh(void *opaque) if (s->event_idx == s->event_max) { do { struct timespec ts = { 0 }; - s->event_max = io_getevents(s->ctx, MAX_EVENTS, MAX_EVENTS, + s->event_max = io_getevents(s->ctx, s->nr_evt, s->nr_evt, s->events, &ts); } while (s->event_max == -EINTR); @@ -201,11 +203,13 @@ static const AIOCBInfo laio_aiocb_info = { .cancel_async = laio_cancel, }; -static void ioq_init(LaioQueue *io_q) +static void ioq_init(LaioQueue *io_q, unsigned size) { - io_q->size = MAX_QUEUED_IO; + io_q->size = size; io_q->idx = 0; io_q->plugged = 0; + + io_q->iocbs = g_malloc(sizeof(*io_q->iocbs) * size); } static void abort_queue(struct qemu_laio_state *s) @@ -385,16 +389,34 @@ static int laio_alloc_resources(AioContext *ctx, struct qemu_laio_state *s) { LaioQueue *ioq; + unsigned nr = s->nr_bs ? : 1; + + /* return immediately if resources are allocated already */ + if (likely(s->io_q)) { + return 0; + } + + if (nr > 10) { + nr = 10; + } + + while (nr > 0) { + if (io_setup(MAX_EVENTS * nr, &s->ctx) == 0) { + break; + } + nr--; + } - if (io_setup(MAX_EVENTS, &s->ctx) != 0) { + if (nr == 0) { return -1; } + s->nr_evt = nr * MAX_EVENTS; ioq = g_malloc0(sizeof(*s->io_q)); - ioq_init(ioq); + ioq_init(ioq, MAX_QUEUED_IO * nr); ioq->retry = aio_bh_new(ctx, ioq_submit_retry, s); - s->events = g_malloc(sizeof(*s->events) * MAX_EVENTS); + s->events = g_malloc(sizeof(*s->events) * s->nr_evt); s->io_q = ioq; s->completion_bh = aio_bh_new(ctx, qemu_laio_completion_bh, s); @@ -464,6 +486,7 @@ void laio_detach_aio_context(void *s_, BlockDriverState *bs, } } + qs->state->nr_bs--; if (!aio_detach_aio_bs(old_context, bs)) { /* assign new master aio bs for the aio context */ if (old_context->master_aio_bs == bs) { @@ -494,6 +517,7 @@ void laio_attach_aio_context(void *s_, BlockDriverState *bs, tbs->bs = bs; QLIST_INSERT_HEAD(&qs->state->tracked_bs, tbs, list); + qs->state->nr_bs++; } void *laio_init(void) -- 1.7.9.5