[mythtv-users] mythbackend and mythwelcome wakeup a lot (powertop report)

[David Rees]

I upgraded my FC6 MythTV system to F7 over the weekend and ran
powertop to see how well  or poorly the system does. I'm using 0.20
RPMs from Atrpms.  It turns out that mythfrontend and mythbackend wake
up an awful lot (mythfrontend not running at the time):

43.8% (170.4) mythwelcome : schedule_timeout (process_timeout)
26.3% (102.2) mythbackend : schedule_timeout (process_timeout)
19.5% ( 75.6) <interrupt> : ivtv0, nvidia
5.1% ( 20.0) mythbackend : futex_wait (hrtimer_wakeup)
0.9% ( 3.5) wmaker : schedule_timeout (process_timeout)
0.9% ( 3.4) X : do_setitimer (it_real_fn)

I opened a ticket: http://svn.mythtv.org/trac/ticket/3800

Anyone else running F7 care to share how their system does?

I found one other reference to powertop by searching the archives
which show a similar number of wakeups from mythbackend:
http://mythtv.org/pipermail/mythtv-users/2007-July/186094.html

My hardware (Sempron 3000) doesn't seem to benefit much from reducing
the number of wakeups according to my Kill-A-Watt as it doesn't seem
to support lower C-states, but I would expect hardware that supports
C3 or C4 CPU states to save a couple watts by reducing the number of
wakeups.

-Dave