Re: Latest Power Management tool for AMD64
Thank you thveillon.debian for the comment, and Dave for the detailed
explanation.
On Thu, 19 Mar 2009 07:37:15 -0400, Dave Witbrodt wrote:
> The default kernel governor is ONDEMAND, so Tong has probably been using
> CPU frequency controls all along without knowing it. :)
Not after I've installed a bunch of packages that google implies
necessary, because I'm using a minimum set of packages.
What are the minimum set of packages to enable kernel space cpufreq
ondemand governor?
> In the case of 'powernowd', for example, it is possible to control
> things like:
>
> - polling time (how often frequency adjustments are made) - upper and
> lower CPU usage thresholds (which control the decision
> about whether to step CPU frequency up or down)
> - step size (how much frequency is altered when stepped up or down...
> though this is very much constrained by hardware limitations)
> - mode (basic behavior of the CPU governor)
What's your current frequency limits, and step sizes?
Having enabled my kernel ondemand cpufreq governor, this is what I get:
$ cpufreq-info | grep frequency
CPUs which need to switch frequency at the same time: 0 1
available frequency steps: 2.30 GHz, 2.20 GHz, 2.00 GHz, 1.80 GHz,
1000 MHz
current policy: frequency should be within 1000 MHz and 2.30 GHz.
current CPU frequency is 1000 MHz (asserted by call to hardware).
Can I further lower the 1000 MHz boundary any way?
> The 'powernowd' software defaults to "aggressive" mode, which jumps the
> CPU frequency to maximum when the upper threshold on CPU usage is
> reached. This is what I use, and I set both the lower and upper
> boundaries quite low in order to kick the CPU into high gear easily, and
> keep it there as long as anything is going on.
That's similar to the "performance" governor of cpufreq, which is what I
got by default after having crazily installed a bunch of packages:
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
performance
However, the CPU frequency was still very high, even my CPU utilization
was near 0% for quite a long time:
$ grep MHz /proc/cpuinfo
cpu MHz : 2300.000
> so I
> had to add a couple of lines to /etc/modules to make the appropriate
> kernel modules available at boot:
I haven't reboot yet, and don't know if I need to do such manual
adjusting after reboot, for my kernel ondemand cpufreq governor.
Thanks
--
Tong (remove underscore(s) to reply)
http://xpt.sourceforge.net/techdocs/
http://xpt.sourceforge.net/tools/
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