Re: [Xen-users] Poor Windows 2003 + GPLPV performance compared to VMWare

[Adam Goryachev <mailinglists@xxxxxxxxxxxxxxxxxxxxxx>]

On 19/09/12 18:41, Ian Campbell wrote:
> On Tue, 2012-09-18 at 14:06 +0100, Adam Goryachev wrote:
>> On 15/09/12 00:53, Adam Goryachev wrote:
>>> On 14/09/12 23:30, Ian Campbell wrote:
>>>
>>>>>>> device_model    = '/usr/lib/xen-default/bin/qemu-dm'
>>>>>>> localtime    = 1
>>>>>>> name        = "vm1"
>>>>>>> cpus        = "2,3,4,5"    # Which physical CPU's to allow
>>>>>> Have you pinned dom0 to use pCPU 1 and/p pCPUs > 6?
>>>>> No, how should I pin dom0 to cpu0 ?
>>>> dom0_vcpus_pin as described in
>>>> http://xenbits.xen.org/docs/4.2-testing/misc/xen-command-line.html
>>> Thanks, I'll need to reboot the dom0 to apply this, will do as soon as
>>> this current scheduled task is complete.
>> OK, I have pinned dom0 to cpu0, and this had no effect on performance.
>>>> You have:
>>>>         cpus = "2,3,4,5"
>>>> which means "let all the guests VCPUs run on any of PCPUS 2-5".
>>>>
>>>> It sounds like what you are asking for above is:
>>>>         cpus = [2,3,4,5]
>>>> Which forces guest vcpu0=>pcpu=2, 1=>3, 2=>4 and 3=>5.
>>>>
>>>> Subtle I agree.
>>> Ugh... ok, I'll give that a try. BTW, it would seem this is different
>>> from xen 4.0 (from debian stable) where it seems to magically do what I
>>> meant to say, or I'm just lucky on those machines :)
>> Actually, the above syntax doesn't work:
>> cpus        = [2,3,4,5]    # Which physical CPU's to allow
>> Error: 'int' object has no attribute 'split'
> Is it ["2","3"...] then I wonder?
>
>> Once I reverted to:
>> cpus    = "2,3,4,5"
>> I can then boot again, but on reboot I get this:
>> xm vcpu-list
>> Name                                ID  VCPU   CPU State   Time(s) CPU
>> Affinity
>> Domain-0                             0     0     0   r--     148.9 0
>> cobweb                               6     0     5   ---       0.5 2-5
>> cobweb                               6     1     -   --p       0.0 2-5
>> cobweb                               6     2     -   --p       0.0 2-5
>> cobweb                               6     3     -   --p       0.0 2-5
>>
>> So it isn't pinning each vcpu to a specific cpu... but I suppose it
>> should be smart enough to do it well anyway...
>> Performance is still at the same level.
> To be honest I wouldn't expect it to make much difference at this stage.
>
> I notice the state is "--p" for all but VCPU0 -- which means they are
> paused.
>
> It's probably just that you ran the xm vcpu-list before Windows booted
> as far as brining up secondary CPUs but it would be worth checking that
> Windows is actually bringing up / using all the CPUs!
>
> Once the VM is fully booted then the state for each vcpu should either
> be "r--" (running) or "-b-" (currently blocked). I presume something
> like Windows task manager will also confirm that all the CPUs are in
> use.
That's correct, cpu time was only .5s, so very likely it was pretty
immediately after I did the create. Once the machine is up and running I
see all 4 vcpu's in b or r state, and the cpu time column incrementing.
Within Windows task manager I also see all 4 vcpu's being used during
the process I am running. Windows reports approx 50% cpu utilisation,
and that actually equates fairly well to 50% of each vcpu, ie, the work
load is well balanced across all 4 cores (I don't know if that is by
chance, etc... but it is good).

I've updated to SP2, and will re-test in the next few hours, failing
that, I'll move back to performance measuring with fio/etc.

Thanks for all the suggestions and help so far I really appreciate it.

Regards,
Adam

-- 
Adam Goryachev
Website Managers
www.websitemanagers.com.au


_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxx
http://lists.xen.org/xen-users