[fedora-virt] F12 and ksm/ksmtuned: info required...

[kashyap chamarthy]

On 11/24/2009 05:31 PM, Gianluca Cecchi wrote:
> On Tue, Nov 24, 2009 at 12:50 PM, Dan Kenigsberg<danken at redhat.com>  wrote:
>>
>> yes, the purpose of ksmtuned is to tune ksm parameters, or stop it
>> altogether if it is not needed. In case your two virtual machines
>> required less than available memeory, ksm is not used. If ksmtune senses
>> that memory stress has risen, it fires up ksm again.
>>
>> I don't think this is written anywhere but in the code.. We probably
>> should add something to the "User experience" section to that feature page.
>> How about:
>>
>> Fedora's kvm comes with 2 services controlling the behavior of ksm. One,
>> simply called ksm, is just a nice means to start and stop ksm's kernel
>> thread. The other, called ksmtuned, controls the first service and tunes
>> its parameters according to the memory stress that is generated by KVM
>> virtual machines.
>>
>
> It sounds good; I would only add something like this:
>
> "In case of need, e.g. in minor load situations, ksmtuned can also
> stop ksm service at all.
> Later, if ksmtuned senses that memory stress has risen, it will fire
> up ksm again."
>
> So that one knows that to monitor the status of ksm is not a good idea
> in general.....
> Any log configurable to see/trace ksmtuned decisions (start ksm, stop
> ksm, increase pages...)?

yes, configuratble log/trace info for ksm/ksmtuned would be useful.

I see this for configuration stuff - /etc/ksmtuned.conf

/kashyap

>
> Gianluca
>
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