Re: [moose-devel] CPU usage in the idle state and also not using cpu in execution time effectively

[Subhasis R. <ray...@gm...>]

On Fri, Nov 23, 2012 at 12:06 AM, Saeed Shariati <s.s...@uf...>wrote:

> After starting application, cpu shows 110% usage (4 core cpu) for do
> nothing!
>

By default MOOSE runs one "command thread" and as many "process threads" as
the number of cores. The worker threads look for data in a queue in a busy
loop. This causes the high CPU usage. This is intended for heavy
simulations where you have different components of a large model simulated
on different threads (and cores). You can set the environment variable
NUMPTHREADS=1 to use only 1 process thread.


> And, when the simulation start, it increases near to 220%.
>

That is understandable.


>
> It seems that everything executes on Python.
>

No. Python just sets up the simulation and starts by calling C++ functions.
When you say moose.start(time) in Python, that is a C++ function running
the entire simulation.


> Is it possible to execute the simulation code in a more efficient way?
>

You can look at the regressionTests directory for some examples where the
simulations are executed in C++ without Python.
I would also suggest you read the Programmers guide [
http://moose.ncbs.res.in/index.php?option=com_wrapper&Itemid=65], the
application programming API and the design document to get a handle on the
internals of MOOSE.

Best,
 Subha