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

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"