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 <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20161201192652.9509-6-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2016-12-01 19:26:44 +00:00
parent 0062ea0fd6
commit ee68697551

View file

@ -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)