[Python-Dev] Reworking the GIL

[Stefan Ring]

Hello,

I built something very similar for my company last year, and it’s been running
flawlessly in production at a few customer sites since, with avg. CPU usage ~50%
around the clock. I even posted about it on the Python mailing list [1] where
there was almost no resonance at that time. I never posted code, though --
nobody seemed to be too interested.

I am well aware that your current work is a lot more far-reaching than what I’ve
done, which is basically just a FIFO scheduler. I even added scheduling
priorities later which don’t work too great because the amount of time used for
a "tick" can vary by several orders of magnitude, as you know.

Thought you might be interested.

Regards
Stefan

[1] http://mail.python.org/pipermail/python-dev/2008-March/077814.html
[2] http://www.bestinclass.dk/index.php/2009/10/python-vs-clojure-evolving/
[3] www.dabeaz.com/python/GIL.pdf

PS On a slightly different note, I came across some Python bashing [2] yesterday
and somehow from there to David Beazley’s presentation about the GIL [3]. While
I don’t mind the bashing, the observations about the GIL seem quite unfair to me
because David’s measurements have been made on Mac OS X with its horribly slow
pthreads functions. I was not able to measure any slowdown on Linux.