Lower power portable Linux

[Dave Johnson]

Mark Komarinski writes:
> It's better now, for the most part.
> 
> A few drivers still don't suspend and resume properly, but there are
> often workarounds like removing them before suspending.  Utilities
> like powertop can help identify what's causing the CPU or other
> subsystems to be drawing more power than needed. 
> 
> Using it, I was able to get my IBM x40 from about 14W to about 10W.
> 
> Some of the recommendations  from powertop are 'obvious' like using
> noatime.  Others include things like lowering the Tx power for the
> wifi card or disabling bluetooth if it's not in use. 

Ya, powertop is a very good start.  Mostly to point how badly some
userspace programs are written to poll for stuff or use usleep() loops
instead of being event driven.

Using it I was able to get from about 400 wakeups/sec while idle to
about 90-100 wakeups/sec.  40 of those are from 2 badly written
programs that each do a 50ms usleep() loop. Another 10 from ipw2200,
and 10 from acpi periodic interupts. Plus 10 from an xterm for some
reason.

-- 
Dave