xen: actually release memory when shrinking domain

Fix this:

> It appears that in the upstream balloon driver,
> the call to HYPERVISOR_update_va_mapping is missing
> from decrease_reservation.  I think as a result,
> the balloon driver is eating memory but not
> releasing it to Xen, thus rendering the balloon
> driver essentially useless.  (Can be observed via xentop.)

Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Dan Magenheimer 2009-01-22 14:36:08 -08:00 committed by Ingo Molnar
parent 066941bd4e
commit 1058a75f07

View file

@ -298,6 +298,11 @@ static int decrease_reservation(unsigned long nr_pages)
frame_list[i] = pfn_to_mfn(pfn);
scrub_page(page);
ret = HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT),
__pte_ma(0), 0);
BUG_ON(ret);
}
/* Ensure that ballooned highmem pages don't have kmaps. */