Re: [Qemu-discuss] Puzzling performance comparison with KVM and Hyper-V

[Carlos Torres]

________________________________________
From: Tim Bell <address@hidden>
Sent: Tuesday, July 21, 2015 9:53 AM
To: Stephan von Krawczynski
Cc: Carlos Torres; address@hidden
Subject: Re: [Qemu-discuss] Puzzling performance comparison with KVM and Hyper-V

On Tue, 21 Jul 2015, Stephan von Krawczynski wrote:

> On Tue, 21 Jul 2015 16:16:22 +0200
> Tim Bell <address@hidden> wrote:
>
>>
>>
>> On Tue, 21 Jul 2015, Carlos Torres wrote:
>>
>>> On Jul 21, 2015 5:45 AM, Tim Bell <address@hidden> wrote:

>
> Have you worked out the pinning? The cpu numbers are _not_ in line with
> core/SMT distribution over the physical dies.
>

I think we did it correctly but please give me some pointers to check...
the vCPU to CPU mapping we used was as below

vCPU:CPU
0: 0
1: 1
2: 2
3: 3
4: 4
5: 5
6: 6
7: 7
8: 16
9: 17
10: 18
11: 19
12: 20
13: 21
14: 22
15: 23
16: 8
17: 9
18: 10
19: 11
20: 12
21: 13
22: 14
23: 15
24: 24
25: 25
26: 26
27: 27
28: 28
29: 29
30: 30
31: 31

>
> --
> Regards,
> Stephan
>

Hi Tim,

'cat /proc/cpuinfo' should give you this information, look at the processor, 
physical id and core id values

For example, here's an excerpt from my laptop that has 4 physical cores up to 2 
threads per core (8 cpus total).

processor       : 0                         <=== CPU # given by the OS
vendor_id       : GenuineIntel
.....
physical id     : 0                         <==== Physical Processor Socket ID
siblings        : 8
core id         : 0                           <==== Physical CPU Core ID
cpu cores       : 4
....

processor       : 1                      
vendor_id       : GenuineIntel
.....
physical id     : 0                        <=== Same Processor socket (my 
laptop has only 1)
siblings        : 8
core id         : 1                          <==== Distinct CPU Physical core
cpu cores       : 4

....

processor       : 4                    
vendor_id       : GenuineIntel
.....
physical id     : 0                      <=== Still same Processor socket 
(expected)
siblings        : 8
core id         : 0                        <=== Note this is the same physical 
core as processor 0 above
cpu cores       : 4


-- Carlos Torres