Re: performance tuning, problem with paravirtualized clock

Nikola Ciprich
2008-04-07T20:47:47Z

Hi Marcelo!

>> Host machine: 2x quad core XEON E5420 @ 2.50GHz, 4GB RAM, 2.6.24 + kvm-64
>> guest configuration: all 8 cores available, 2GB RAM, 2.6.24 or latest GIT
>> + kvm-64

> Can you please provide more details on this? Which kernel version are
> you running on the host?
As I wrote, I use 2.6.24 for the host (+ kvm-65 at the moment), and I'm
trying both 2.6.24 and git for the guest.
>
> Please try -git (there was a lock inversion problem in the KVM clock
> which could cause lock ups).
Unfortunately the problem persists with today's git with kvm-65 patch
applied.

> You might want to pin each guest VCPU to a physical host CPU and check
> if that makes a difference.
It seems that processes are divided on cores quite well, but I'll try
pinning them explicitly to be sure...