Hello,

About the Morphic rendering loop, the delay between rendering is handled in WorldState>>#interCyclePause:. The best solution to reduce the cost of the Morphic rendering loop is to put it in server mode by executing in Pharo: WorldState��serverMode: true. In squeak you have to set that in the Preferences.

But as it was discussed, the cpu consumption most probably does not come from Morphic but comes from the idle loop, which can be solved by doing an event-driven VM.��

I am particularly willing to have an event-driven VM because it then means that the VM performance would then be directly proportional to the cpu consumption. For example, theoretically, with an event-driven VM, having the VM twice faster with Spur would also mean that the VM consumes twice less energy. Go Green IT :-)

2015-02-10 8:00 GMT+01:00 Eliot Miranda <eliot.miranda@gmail.com>:



On Feb 9, 2015, at 10:41 PM, Sven Van Caekenberghe <sven@stfx.eu> wrote:

>
>> On 10 Feb 2015, at 01:55, Eliot Miranda <eliot.miranda@gmail.com> wrote:
>>
>> Hi Sven,
>>
>> On Mon, Feb 9, 2015 at 1:43 PM, Sven Van Caekenberghe <sven@stfx.eu> wrote:
>> There is some timer thread between the image and the vm that ticks every millisecond, that is the cause. I don't know what it does but it is apparently needed.
>>
>> Anyway, that is how I understood it from Igor and Eliot, long ago.
>>
>> So basically, the VM is always slightly busy.
>>
>> Yet the VM is always slightly busy with the heartbeat thread, but this is very cheap.�� The actual idle cost comes form the idle loop in the background process that sends relinquishProcessorForMicroseconds:, which is a primitive that eventually calls the select system call.�� This is the source of the cost.
>
> Can we change something about that ?
> Maybe just as an experiment to prove your point ?

What do you think halving or doubling the argument to relinquishProcessorForMicroseconds: should do if this is the major source of overhead?�� Processor usage at idle should be closely inversely proportional right?

>
>>> On 09 Feb 2015, at 21:11, Norbert Hartl <norbert@hartl.name> wrote:
>>>
>>> I have an installation where a pharo powered hardware is used in a closed case. Over time that collects quite some heat. One reason for this is that the pharo vm is taking approx. 6% CPU all the time. The only thing that happens is network/sockets. I suspended the ui thread in the image but on this platform it doesn't help.
>>> Are there any tweaks to lower the polling and the activity of the image/vm even more?
>>>
>>> thanks,
>>>
>>> Norbert
>> --
>> best,
>> Eliot
>
>