[Tfug] Re-nice... erm, and runlevels.

[Jeremy D Rogers]

On Thu, Mar 12, 2009 at 12:57 AM, Brian Murphy
<murphy+tfug at email.arizona.edu> wrote:
> Quoting Jeremy D Rogers <jdrogers at optics.arizona.edu>:
>>
>> I still feel like a runlevel should be dedicated to low-power mode for
>> laptops whereby switching runlevels removed power-hungry modules and
>> set certain hardware into low power mode, or standby and shutdown
>> unneeded services that otherwise keep spinning up disks. Especially
>> stuff like 3D graphics drivers and various services. Laptopmode is one
>> thing, but it just seems like runlevels would be a powerful tool for
>> changing such a state of the system, and you could still have a
>> config/updatescript that allows choice of what gets switched on/off.
>
>
> From what I've read on various lists, people working on power efficiency
> want their improvements made to all systems.  Laptops are just the
> obvious case.

True, true. I absolutely want my workstation to be efficient. I use
hibernate on my home desktop / myth box so I can have a quick resume.
Low power states are great, but I was more thinking of things more
drastic, like stopping servers that are likely useless when on an
airplane where all radio is off anyway. Imagine an airplane-mode
runlevel... all radio is off, no network, so shutdown all services and
daemons related to networking (less proc wakeups, better on the
c-states, longer sleeps, etc.). Switch from the nifty radeon 3D driver
that allows compiz and 3D to vesa or better yet some 2D version that
drops the clock rate, etc.

I've tinkered with this on long flights with my T60.  I know that with
all my laptop-mode stuff turned on, but using a 3D radeon driver, I
can get my laptop down to 17W (according to the smapi battery info).
However, if I unload all possible modules, stop all services, use the
vesa driver, etc, I can get it down to 11W. On a workstation, you
still need those services and so forth, but on a long flight, that
take me from 3.3 to 5 hours. That seems like a lot.

> Matthew Garrett has blogged some interesting things about it (like
> screensavers: http://mjg59.livejournal.com/106581.html).  Here is where
> he sums up some power saving tips:
>
> http://www.codon.org.uk/~mjg59/power/good_practices.html

Thanks for the links, some good info there. I'll have to play with
some of that when I get a chance. I also like:
http://www.thinkwiki.org/wiki/How_to_reduce_power_consumption
which has some thinkpad specific stuff, but also a lot of general info
worth looking at too.

> Brian
>
> The opinions or statements expressed herein are my own and should not be
> taken as a position, opinion, or endorsement of the University of
> Arizona.
>
>
>
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