From ee68697551cd81186c5b12eba10c158350cf1165 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Thu, 1 Dec 2016 19:26:44 +0000 Subject: [PATCH] linux-aio: poll ring for completions The Linux AIO userspace ABI includes a ring that is shared with the kernel. This allows userspace programs to process completions without system calls. Add an AioContext poll handler to check for completions in the ring. Signed-off-by: Stefan Hajnoczi Reviewed-by: Paolo Bonzini Message-id: 20161201192652.9509-6-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi --- block/linux-aio.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/block/linux-aio.c b/block/linux-aio.c index 69c4ed52ca..03ab741d37 100644 --- a/block/linux-aio.c +++ b/block/linux-aio.c @@ -255,6 +255,20 @@ static void qemu_laio_completion_cb(EventNotifier *e) } } +static bool qemu_laio_poll_cb(void *opaque) +{ + EventNotifier *e = opaque; + LinuxAioState *s = container_of(e, LinuxAioState, e); + struct io_event *events; + + if (!io_getevents_peek(s->ctx, &events)) { + return false; + } + + qemu_laio_process_completions_and_submit(s); + return true; +} + static void laio_cancel(BlockAIOCB *blockacb) { struct qemu_laiocb *laiocb = (struct qemu_laiocb *)blockacb; @@ -448,7 +462,8 @@ void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context) s->aio_context = new_context; s->completion_bh = aio_bh_new(new_context, qemu_laio_completion_bh, s); aio_set_event_notifier(new_context, &s->e, false, - qemu_laio_completion_cb, NULL); + qemu_laio_completion_cb, + qemu_laio_poll_cb); } LinuxAioState *laio_init(void)