[Python-Dev] Signals+Threads (PyGTK waking up 10x/sec).

[Andrew Bennetts]

Guido van Rossum wrote:
> On Dec 11, 2007 4:54 PM, Jan Claeys <lists at janc.be> wrote:
> > Op vrijdag 07-12-2007 om 07:26 uur [tijdzone -0700], schreef Sean
> > Reifschneider:
> > > I would say that this is an optimization that helps a specific set of
> > > platforms, including one that I think we really care about, the OLPC
> > > which needs it for decreased battery use.
> >
> > Almost every laptop user would benefit from it, and even some desktop or
> > server users might save on their electric power bill...
> 
> Do you have data to support this claim?

http://www.lesswatts.org/projects/powertop/powertop.php

Some quotes plucked from that page:

“In the screenshot, the laptop isn't doing very well. Most of the time the
processor is in C2, and then only for an average of 4.4 milliseconds at a time.
If the laptop spent most of its time in C4 for at least 20 milliseconds, the
battery life would have been approximately one hour longer.”

“When running a full GNOME desktop, 3 wakeups per second is achievable.”

There's considerable effort being invested in the GNOME and Linux software stack
at the moment to get rid of unnecessary CPU wakeups, and people are reporting
significant improvements in laptop power consumption as a result of that work.

-Andrew.