Overcoming python performance penalty for multicore CPU

[Martin v. Loewis]

> It's far from scientific, but I've seen behaviour that's close to a 100%
> performance penalty on a dual-core linux system:
> 
>    http://www.rfk.id.au/blog/entry/a-gil-adventure-threading2
> 
> Short story:  a particular test suite of mine used to run in around 25
> seconds, but a bit of ctypes magic to set thread affinity dropped the
> running time to under 13 seconds.

Indeed, it's not scientific - but with a few more details, you could
improve it quite a lot: what specific Linux distribution (the posting
doesn't even say it's Linux), what specific Python version had you been
using? (less important) what CPUs? If you can: what specific test suite?

A lot of science is about repeatability. Making a systematic study is
(IMO) over-valued - anecdotal reports are useful, too, as long as they
allow for repeatable experiments.

Regards,
Martin