On Thursday 17 January 2008 13:14:58 Anthony Liguori wrote:
> Rusty Russell wrote:
> > +static struct virtio_device_id id_table[] = {
> > + { VIRTIO_ID_BALLOON, VIRTIO_DEV_ANY_ID},
>
> Could use a space after VIRTIO_DEV_ANY_ID
Thanks, fixed.
> > + __free_page(page);
> > + vb->num_pages--;
> > + totalram_pages++;
>
> Do we really want to modify totalram_pages in this driver? The only
> other place that I see that modifies it is in mm/memory_hotplug and it
> also modifies other things (like num_physpages). The cmm driver doesn't
> touch totalram_pages.
I don't think there's a standard here, they're all ad-hoc (eg. no locking)
Modifying totalram_pages has the nice effect of showing up in "free" in the
guest.
We should probably not modify num_physpages, because some places seem to use
it as an address space limit. But we should probably fix all those
networking size heuristics to use totalram_pages instead of num_physpages.
> It would be very useful too to write vb->num_pages into the config space
> whenever it was updated. This way, the host can easily keep track of
> where the guest is at in terms of ballooning.
OTOH it's currently pretty obvious (and usually fatal) if the guest has
trouble meeting the balloon requirements. A serious host needs a way of
detecting stress in the guest anyway, which this doesn't offer until it's too
late...
Rusty.
_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linux-foundation.org/mailman/listinfo/virtualization
