On Fri, Sep 13, 2013 at 10:14 AM, M.-A. Lemburg <mal@python.org> wrote:

On 12.09.2013 21:51, Giampaolo Rodola' wrote:

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On Thu, Sep 12, 2013 at 9:32 PM, Antoine Pitrou <solipsis@pitrou.net> wrote:

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Then the question is whether having physical CPU cores count can be useful.

I suppose it doesn't hurt :-) I don't think it belongs specifically in multiprocessing, though. Perhaps in the platform module?

I'd be +0.5 for multiprocessing because:

- cpu_count() is already there - physical_cpu_count() will likely be used by multiprocessing users only

...but my main concern was first figuring out whether it might actually make sense to distinguish between virtual and physical CPUs in a real world app.

I'm with Antoine here: both APIs would make more sense in the platform module.

In the end it appears the os module would probably be better as cpu_count() already ended up there (http://bugs.python.org/issue17914) as pointed out by Victor a couple of emails ago. I have the impression no one is opposed so I can probably start working on a patch and submit it on the bug tracker.

Do you need C code for determining the physical count ?

Yes, except on Linux where you'll just read /proc/cpuinfo.

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(unless you want to contribute psutil to the stdlib?)

That's something I'd be happy to do if there's general approval but I guess that's for another thread.

I'd love to see psutils in the stdlib, but also be warned: once the code lives in the stdlib,

a) making changes is difficult and adding new features as well,

b) you are bound by the Python release cycle.

For a package such psutil, it may actually be better to keep it outside the stdlib, since the outside world changes regularly and doesn't adhere to the Python release cycle or feature for patch level releases ;-)

Yeah, you're probably right,and there's at least a couple of high priority functionalities I'd like to add first (to say one: dragonfly/open/net BSD support). --- Giampaolo https://code.google.com/p/pyftpdlib/ https://code.google.com/p/psutil/ https://code.google.com/p/pysendfile/