On 26.03.2012 20:36, Vadim Rozenfeld wrote:
On Monday, March 26, 2012 07:52:49 PM Gleb Natapov wrote:
On Mon, Mar 26, 2012 at 07:46:03PM +0200, Vadim Rozenfeld wrote:
On Monday, March 26, 2012 07:00:32 PM Peter Lieven wrote:
On 22.03.2012 10:38, Vadim Rozenfeld wrote:
On Thursday, March 22, 2012 10:52:42 AM Peter Lieven wrote:
On 22.03.2012 09:48, Vadim Rozenfeld wrote:
On Thursday, March 22, 2012 09:53:45 AM Gleb Natapov wrote:
On Wed, Mar 21, 2012 at 06:31:02PM +0100, Peter Lieven wrote:
On 21.03.2012 12:10, David Cure wrote:
hello,
Le Tue, Mar 20, 2012 at 02:38:22PM +0200, Gleb Natapov ecrivait :
Try to add<feature policy='disable' name='hypervisor'/> to
cpu definition in XML and check command line.
ok I try this but I can't use<cpu model> to map the host cpu
(my libvirt is 0.9.8) so I use :
<cpu match='exact'>
<model>Opteron_G3</model>
<feature policy='disable' name='hypervisor'/>
</cpu>
(the physical server use Opteron CPU).
The log is here :
http://www.roullier.net/Report/report-3.2-vhost-net-1vcpu-cpu.tx
t.gz
And now with only 1 vcpu, the response time is 8.5s, great
improvment. We keep this configuration for production : we check
the response time when some other users are connected.
please keep in mind, that setting -hypervisor, disabling hpet and
only one vcpu
makes windows use tsc as clocksource. you have to make sure, that
your vm is not switching between physical sockets on your system
and that you have constant_tsc feature to have a stable tsc
between the cores in the same socket. its also likely that the
vm will crash when live migrated.
All true. I asked to try -hypervisor only to verify where we loose
performance. Since you get good result with it frequent access to
PM timer is probably the reason. I do not recommend using
-hypervisor for production!
@gleb: do you know whats the state of in-kernel hyper-v timers?
Vadim is working on it. I'll let him answer.
It would be nice to have synthetic timers supported. But, at the
moment, I'm only researching this feature.
So it will take months at least?
I would say weeks.
Is there a way, we could contribute and help you with this?
Hi Peter,
You are welcome to add an appropriate handler.
I think Vadim refers to this HV MSR
http://msdn.microsoft.com/en-us/library/windows/hardware/ff542633%28v=vs.85
%29.aspx
This one is pretty simple to support. Please see attachments for more details.
I was thinking about synthetic timers http://msdn.microsoft.com/en-
us/library/windows/hardware/ff542758(v=vs.85).aspx
is this what microsoft qpc uses as clocksource in hyper-v?
i will check tomorrow.
thanks
vadim
--
Gleb.
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