Re: [Xen-users] Xen 4.1 and 3.0 kernel CPU performance

[Todd Deshane <todd.deshane@xxxxxxx>]

On Sat, Oct 15, 2011 at 4:21 AM, Kommeri Jukka <jukka.kommeri@xxxxxxxx> wrote:
> Hello all,
>
> I have been running different benchmarks on paravirtualized domU. I have run
> into strange performance drops with CPU intesive benchmarks (64-bit
> BurnInSSE & 64-bit Linpack test).
>
> With Linpack test the performance of Xen is 90% of hardware where KVM is
> only about 1-2% worse than hardware. This is something new to me as I am
> used to better performance with older Xen versions.
>

Linux 3.0 is not performance optimized yet. There are some known bugs.
Many of which are fixed in newer versions.

See: http://wiki.xen.org/xenwiki/Linux_30_bugs

For more hints on tweaking things see:
http://wiki.xen.org/xenwiki/XenParavirtOps

Can you provide us with more details of your setup so that we can give
you more suggestions?

It would be better to be testing the newest Linux kernel, since a lot
of changes have gone in since Linux 3.0

> I have a Dell R410 with two Xeon E5520 processors and I am running Ubuntu
> Lucid on both domU and dom0. The Xen settings are pretty much default,
> though I did try varying credit scheduler weights without any success.
>
> Has anybody else noticed the same or have I just forgot something essential
> from my kernel?
>
> Best regards,
> Jukka Kommeri
>
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>



-- 
Todd Deshane
http://www.linkedin.com/in/deshantm
http://www.xen.org/products/cloudxen.html
http://runningxen.com/

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