Re: [Xen-users] Xen VMs and Unixbench: single vs multiple cpu behaviour

[Marko ÄukiÄ <marko.djukic@xxxxxxxxx>]

The host is a normal desktop machine with a 4 core CPU (Intel Core i5 4460), no hyperthreading.

Here are the complete UnixBench results of one of the iterations:

*******************

1 cpu VM (test A):

Dhrystone 2 using register variables    Â3403.6

Double-Precision Whetstone          785.5

Execl Throughput                 Â1853.5

File Copy 1024 bufsize 2000 maxblocks Â3909.4

File Copy 256 bufsize 500 maxblocks   Â2468.3

File Copy 4096 bufsize 8000 maxblocks Â6212.0

Pipe Throughput                  Â2079.8

Pipe-based Context Switching        Â1101.3

Process Creation                  1811.4

Shell Scripts (1 concurrent) Â Â Â Â Â Â Â Â Â Â3084.2

Shell Scripts (8 concurrent) Â Â Â Â Â Â Â Â Â Â2838.6

System Call Overhead             Â3511.4

System Benchmarks Index Score     Â2407.4

*******************

4 cpu VM:

single copy of tests (test B-1):

Dhrystone 2 using register variables    Â3355.0

Double-Precision Whetstone          Â787.6

Execl Throughput                  298.8

File Copy 1024 bufsize 2000 maxblocks 3292.7

File Copy 256 bufsize 500 maxblocks   2078.2

File Copy 4096 bufsize 8000 maxblocks 5516.9

Pipe Throughput                  1855.9

Pipe-based Context Switching         999.9

Process Creation                  Â254.4

Shell Scripts (1 concurrent) Â Â Â Â Â Â Â Â Â Â 818.0

Shell Scripts (8 concurrent) Â Â Â Â Â Â Â Â Â Â6493.1

System Call Overhead              2870.2

System Benchmarks Index Score     Â1564.2

Process creation in test B-1 stands out in one more thing.

These are results for process creation of all 10 iterations:

1. 254,4ÂÂ

2. 266,0ÂÂ

3. 285,7ÂÂ

4. 439,2ÂÂ(!)

5. 272,3ÂÂ

6. 260,9ÂÂ

7. 279,4ÂÂ

8. 259,7

9. 265,1

10. 284,2

As you can see, test number 4 stands out quite a bit.

4 copies of test in parallel (test B-2):

Dhrystone 2 using register variables     12668.5

Double-Precision Whetstone          Â3418.7

Execl Throughput                  Â5348.0

File Copy 1024 bufsize 2000 maxblocks  3675.8

File Copy 256 bufsize 500 maxblocks   Â2328.9

File Copy 4096 bufsize 8000 maxblocks  7945.6

Pipe Throughput                   6977.6

Pipe-based Context Switching         3377.5

Process Creation                  3232.4

Shell Scripts (1 concurrent) Â Â Â Â Â Â Â Â Â Â 7304.0

Shell Scripts (8 concurrent) Â Â Â Â Â Â Â Â Â Â 8385.8

System Call Overhead              Â7684.0

System Benchmarks Index Score      Â5362.0

I will do another run and follow your instructions, Dario, and

report the results.

Regards

Marko

On 20 November 2015 at 16:16, Dario Faggioli <dario.faggioli@xxxxxxxxxx> wrote:

On Wed, 2015-11-18 at 03:11 +0000, Kun Cheng wrote:
> Multiple CPU, huh?
>
> Might be a NUMA issue.
>
How so? I mean, that could be the case only if the host is NUMA, which
I don't think it is. In fact, I've checked, and have not found any i5 4
cores CPU that is... However, this is of course Marko's to tell. Marko?

Regards,
Dario

--
<<This happens because I choose it to happen!>> (Raistlin Majere)
-----------------------------------------------------------------
Dario Faggioli, Ph.D, http://about.me/dario.faggioli
Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)

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