multiprocessing vs thread performance

[mk]

Christian Heimes wrote:
> mk wrote:
>> Am I doing smth wrong in code below? Or do I have to use
>> multiprocessing.Pool to get any decent results?
> 
> You have missed an important point. A well designed application does
> neither create so many threads nor processes. 

Except I was not developing "well designed application" but writing the 
test the goal of which was measuring the thread / process creation cost.

> The creation of a thread
> or forking of a process is an expensive operation. 

Sure. The point is, how expensive? While still being relatively 
expensive, it turns out that in Python creating a thread is much, much 
cheaper than creating a process via multiprocessing on Linux, while this 
seems to be not necessarily true on Mac OS X.

> You should use a pool
> of threads or processes.

Probably true, except, again, that was not quite the point of this 
exercise..

> The limiting factor is not the creation time but the communication and
> synchronization overhead between multiple threads or processes.

Which I am probably going to test as well.