Re: slow guest performance with build load, looking for ideas

[Avi Kivity <avi@redhat.com>]

On 06/15/2009 05:15 PM, Erik Jacobson wrote:
>> What is the host cpu type?  On pre-Nehalem/Barcelona processors kvm has
>> poor scalability in mmu intensive workloads like kernel builds.
>>      
>
> Thanks for getting back to me.
>
> Today is pretty booked but I'm going to go find a Nehalem system and try to
> run similar tests to compare.  I'll post my results to this thread.
>
> So if I understand what you're saying: best not to use kvm guests for build
> servers with pre-Nehalem processors.
>    

pre-Nehalem / pre-Barcelona, > 4 vcpus, yes.

> Both systems I used were pre-Nehalem.  Here is a cpuinfo snip from both
> systems I tested on:
>    

Yes, so I expect you're seeing contention on kvm->mmu_lock.

-- 
error compiling committee.c: too many arguments to function