[libvirt] [PATCH v3 0/4] Introduce new cputune event

[Pavel Hrdina]

On 09/15/2014 05:16 PM, Daniel P. Berrange wrote:
> On Mon, Sep 15, 2014 at 05:12:12PM +0200, Pavel Hrdina wrote:
>> This patch series introduce new cputune event to inform
>> management applications about every change of cputune values
>> for running domains.
>>
>> There is missing documentation for all events so the documentation
>> for this event will be part of the patches to document all events.
>
> Do you have any background on the motivation for this feature ?
>

This feature is request from oVirt and they would also like to have 
event for blkdeviotune.

> It would help to understand the use case better in order to decide
> whether this is the right approach for the events. Specifically I
> am wondering whether returning all the values in the event is the
> best way. The alternative would be to have a generic "resource
> tunable changed" event where we just specify the type of data that
> changed, and allow the app to then fetch the new values if they
> actually want them. This would let us deal with all the resource
> tunables in a single event, isntead of having to add more events
> for memory tunables, numa tunables, disk I/O, net I/O etc.
>

This event will return only the values that has been changed, not all 
values that we have for cputune.

Having one "big" event for all tunables is a good idea and with the 
typedParameters it should be easy. Let's say that the event would be 
generic, then the typedParameter's field could be for cputune evetns:

   "cpu.shares"
   "cpu.emulatorpin"
   "cpu.vcpu0"

or for example the blkiodevtune:

   "blkdevio.total_bytes_sec"

etc...

Pavel

> Regards,
> Daniel
>