On Wed, 13 Jan 2010 12:59:25 -0600
Adam Litke <a...@us.ibm.com> wrote:
> > > +/*
> > > + * complete_stats_request - Clean up and report statistics.
> > > + */
> > > +static void complete_stats_request(VirtIOBalloon *vb)
> > > +{
> > > + QObject *stats = get_stats_qobject(vb);
> > > +
> > > + if (vb->stats_request_mode == QEMU_BALLOON_MODE_SYNC) {
> > > + qemu_del_timer(vb->stats_timer);
> > > + monitor_print_balloon(cur_mon, stats);
> > > + monitor_resume(cur_mon);
> > > + } else if (vb->stats_request_mode == QEMU_BALLOON_MODE_ASYNC) {
> > > + monitor_protocol_event(QEVENT_BALLOON, stats);
> > > + }
> > > +
> > > + vb->stats_request_mode = QEMU_BALLOON_MODE_NONE;
> > > +}
> >
> > In the previous thread Anthony raised some issues about the 'cur_mon'
> > usage that made me concerned, because some important code rely on
> > it (read async events).
> >
> > As far as I could check, 'cur_mon' is guaranteed to be the default
> > Monitor which is fine if you're aware of it when putting QEMU to run,
> > but I'm afraid that testing your patch with two Monitors (user and qmp)
> > is not going to work.
> >
> > Maybe not a big deal, but would be good to be aware of potential
> > issues.
>
> I talked to Anthony and will try to fix this up. I just need to start
> passing the monitor pointer around as well.
After doing that you could help us improving the Monitor and check
the other cur_mon usages too :)
> > > -void qemu_balloon(ram_addr_t target)
> > > +int qemu_balloon(ram_addr_t target)
> > > {
> > > - if (qemu_balloon_event)
> > > - qemu_balloon_event(qemu_balloon_event_opaque, target);
> > > + if (qemu_balloon_event) {
> > > + qemu_balloon_event(qemu_balloon_event_opaque, target,
> > > + QEMU_BALLOON_MODE_SYNC);
> > > + return 1;
> > > + } else {
> > > + return 0;
> > > + }
> > > }
> >
> > This is used by do_balloon() right? Which is also used by QMP,
> > shouldn't it also handle async vs. sync?
>
> qemu_balloon always acts synchronously. It does not wait on the guest
> to do anything and it does not return data.
Fine then.
