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

[Kashyap Chamarthy]

On 11/24/2009 09:13 PM, Kashyap Chamarthy wrote:
> On 11/24/2009 08:00 PM, Dan Kenigsberg wrote:
>> 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 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
>>
>> 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.
>
> thanks a lot. will try it.

nice..after applying the patch and uncommenting the below lines in /etc/ksmtuned.conf 
throws ksmtuned activity under/var/log/ksmtuned

# LOGFILE=/var/log/ksmtuned
# DEBUG=1

-------------------------------------------------
[root at foobox ~]# /etc/init.d/ksmtuned restart
Stopping ksmtuned:                                         [  OK  ]
Starting ksmtuned:                                         [  OK  ]
[root at foobox ~]# cat /var/log/ksmtuned
Tue Nov 24 22:40:59 IST 2009: total 4019072
Tue Nov 24 22:40:59 IST 2009: sleep 41
Tue Nov 24 22:40:59 IST 2009: thres 803814
Tue Nov 24 22:41:50 IST 2009: total 4019072
Tue Nov 24 22:41:50 IST 2009: sleep 41
Tue Nov 24 22:41:50 IST 2009: thres 803814
---------------------------------------------------
>
> /kashyap
>
>>
>> Regards,
>>
>> Dan.
>>
>
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