I will be re-doing the whole
test with a 4GB hard limit on the memory (for both the native case and the HVM
case) and also with 2 VCPU allocated for Dom0.
I don’t know what the difference
is in our environments. Maybe he was looking at overall time spent? I am
interested in the maximum jobs/minute which can be an indication of how much
horsepower we can get out of a guest VM.
Any answers for my other
questions?
Best regards,
---Kayvan
From: Xu, Anthony
[mailto:anthony.xu@xxxxxxxxx]
Sent: Thursday, January 31, 2008 5:11 PM
To: Kayvan Sylvan; xen-ia64-devel
Subject: RE: [Xen-ia64-devel] HVM Multi-Processor Performance followup
You
can see the drop in performance starts to get really bad at about 9 CPUs and
beyond
If
you increase guest vCPU number, the bottleneck may be dom0 vCPU number( only
1vCPU for dom0).
You
can try configure two/four vCPU for dom0, the performance may be back.
Alex
said there are ~70% degradation on RE-AIM7,
Your
test result seems much better than his.
What's
the difference of your test environment?
From: xen-ia64-devel-bounces@xxxxxxxxxxxxxxxxxxx
[mailto:xen-ia64-devel-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of Kayvan
Sylvan
Sent: 2008年2月1日 8:57
To: xen-ia64-devel
Subject: [Xen-ia64-devel] HVM Multi-Processor Performance followup
Hi everyone,
A follow-up on the multiprocessor performance benchmark on
HVM guests.
We ran the RE-AIM7 benchmarks on a 5-cell (40 CPU) machine
and a single-cell 8-cpu NEC machine.
Here are the jobs per minute maximums.
You can see the drop in performance starts to get really bad
at about 9 CPUs and beyond.
Questions:
1.
What can I do to help improve this situation?
2.
Are there any other experiments I can run?
3.
What tools/profilers will help to gather more data here?
I am very interested in helping to solve this problem!
Thanks for your ideas and suggestions.
Best regards,
---Kayvan
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Xen performance comparison on
5-Cell NEC machine (each cell with 4 dual-core Itaniums)
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CPUs
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Native
Jobs/Min
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HVM
Jobs/Min
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Overhead
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1
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2037
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1791
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12.08%
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2
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4076
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3615
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11.31%
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3
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6090
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5221
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14.27%
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4
|
8118
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6839
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15.76%
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5
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10119
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8404
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16.95%
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6
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12037
|
9949
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17.35%
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7
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14106
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11095
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21.35%
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8
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15953
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12360
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22.52%
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9
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18059
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13201
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26.90%
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10
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20170
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13742
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31.87%
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11
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21896
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13694
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37.46%
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12
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24079
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13331
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44.64%
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13
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25992
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12374
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52.39%
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14
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28072
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11684
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58.38%
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15
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29931
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11032
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63.14%
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16
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31696
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10451
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67.03%
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The guest OS was CentOS-4.6
with 2GB of memory,
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running under a Dom0 that was
limited to 1 VCPU.
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Xen performance comparison on
1-Cell NEC machine (4 dual core Itanium Montecito)
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CPUs
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Native
Jobs/Min
|
HVM
Jobs/Min
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Overhead
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1
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2037
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1779
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12.67%
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2
|
4067
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3619
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11.02%
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3
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6097
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5344
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12.35%
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4
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8112
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7004
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13.66%
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5
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10145
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8663
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14.61%
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6
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12023
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10213
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15.05%
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7
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14083
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11249
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20.12%
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8
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16182
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12969
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19.86%
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The guest OS was CentOS-4.6
with 2GB of memory,
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running under a Dom0 that was
limited to 1 VCPU.
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