CODEWITHSUNDEEP
pythonpython-3.x
I_like_traffic_lights
I_like_traffic_lights

Reputation: 131

How to run Python code using less than 1% of CPU?

I am developing some Python code for Windows. A criteria is that it will use less than 1% of CPU. I understand that it is impossible to guarantee this all the time due to things like garbage collection, but what would be the best practice to get as close as possible. My current solution is to spread a lot of time.sleep(0.1) around the code, especially in loops. There are, however, obvious problems with this approach.

What other approaches could be taken?

I should also mention that the application has lots of threads in it using the threading library.

EDIT: Setting the process priority is not what I am after.

Upvotes: 1

Views: 1726

Answers (3)

Samuel
Samuel

Reputation: 2490

If the box used for the demonstration is a Windows Server, it can use Windows System Resource Manager for restricting CPU usage below the desired threshold. Trying to force this behavior by code is impossible, unless a Windows API exposes this capability explicitly.

Upvotes: 3

Wladimir Palant
Wladimir Palant

Reputation: 57651

If the goal is to not bother the user then "below 1% CPU" is the wrong approach. What you really want is "don't take time away from other processes but still complete as fast as possible" - that's what "below normal" process priority is for. See http://code.activestate.com/recipes/496767-set-process-priority-in-windows/ for an example of how process priority can be changed for the current process (calling that function with default parameters will do).

For the sales pitch you can show the task manager while the computer is idle ("See? 99%, my application gets lots of work done") and then start some CPU-intensive application ("Almost all CPU time is spent in the application the user is working with, my application simply went into background").

Upvotes: 11

ninjagecko
ninjagecko

Reputation: 91094

It is the job of the operating system to schedule CPU time. Use your operating system's built-in process-limits mechanisms (hopefully they exist on Windows) to restrict your process to <1% CPU.

This style of sprinkling unnecessary sleeps every few lines in the code will make the code terrible to create and extend and maintain, not to mention incredibly inelegant. (Rate-limiting yourself may be useful in very small, limited, critical sections -- for example your program is queuing lots of IO requests and you don't wish to inundate the operating system, you might wish to put a single sleep-until-[condition] in each critical loop which has the potential to inundate the system, but otherwise use extremely sparingly.)

Ideally you would call an API to the appropriate OS mechanisms from within your program when you start up, telling the OS to throttle you appropriately.

Upvotes: 11

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