On Tue, Nov 24, 2009 at 06:43:42PM +0530, kashyap chamarthy wrote:
On 11/24/2009 05:31 PM, Gianluca Cecchi wrote:
>On Tue, Nov 24, 2009 at 12:50 PM, Dan Kenigsberg<danken(a)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
You'd have to apply the following patch to /usr/sbin/ksmtuned for it to
easily log into /var/log/ksmtuned. You'd have to add two lines to
/etc/ksmtuned.conf for this to actually work.
Regards,
Dan.