| |
|
 |
|
 |
|
|
|
| |
|
|
xen-devel
[Xen-devel] Re: A credit scheduler issue
On 30 Jun 2006, at 02:13, Kamble, Nitin A wrote:
While debugging I notice an odd behavior; When running on a 2 CPU
system, dom0 gets 2 vcpus by default. And even if there are no other
domains running in the system, the dom0 vcpus are getting migrated to
different pcpus in the load balance. I think it is due to the
preemption happening in the credit scheduler; and it is not necessary
and is actually wasteful to move vcpus when no of vcpus in the system
are equal to no of pcpus.
I would like to know your thinking about this behavior. Is it an
intended in the design?
I added this small fix to the scheduler to fix this behavior. And with
it I see the stability of Xen improved. Win2003 boot was crashing with
unhandled MMIO error on xen64 earlier with credit scheduler. I am not
seeing that crash with this small fix anymore. It is quiet possible
that there are more bugs I need to catch for HVM domains in the credit
scheduler. And I would like to know your thoughts for this change.
Although you may have spotted a performance bug that should be looked
into (if this migration happens significantly frequently), it *should
not* be a correctness bug! I don't think the fixes for the
HVM-and-credit-sched bugs lie in the credit scheduler itself. :-)
-- Keir
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
|
|
| |
|
Home