22 Nov
2014
22 Nov
'14
1:33 p.m.
On Sat, Nov 22, 2014 at 12:27 PM, Will Godfrey
<willgodfrey(a)musically.me.uk> wrote:
Eventually I found the cause. Going from linux kernel
3.2 to 3.16 :(
This, apparently, does very aggressive CPU frequency scaling. Drop back to 3.2
and all is sweetness and light again.
The question is whether there is a reasonably straightforward way to stop this
behaviour.
You can temporarily disable CPU frequency scaling by running the following:
cpupower frequency-set -g performance
To return to normal "when-needed" CPU frequency scaling (better for
battery / heat)
cpupower frequency-set -g ondemand
This might work too, it "hard-sets" to the lowest CPU speed: generally
switching CPU freq causes the xruns, not the actual slow-setting
itself. Useful for battery performance.
cpupower frequency-set -g powersave
Note that frequency scaling is currently broken on newest -rt kernels
on *old* CPU's. ArchAudio repositories have a hard-coded "performance"
-rt kernel, which sets the default speed to max: thanks JackWinter for
packaging that!
Cheers, -Harry
--
http://www.openavproductions.com