[ltp] Frustrating powertop results for a22m
Connor Behan
linux-thinkpad@linux-thinkpad.org
Thu, 14 Feb 2008 15:09:08 -0500
If I run Powertop when X is running, about 50% of my wakeups say "extra
timer interrupt" and if X is not running, about 80% of them say that.
All of the suggestions online of how to fix this say to enable CPU
frequency scaling and to set HPET as the timer.
My a22m has a 900Mhz Mobile Pentium III with Speedstep according to
Thinkwiki. However, I tried to load cpufreq modules and the only one
that will load is speedstep-lib and I need one like speedstep-smi or
speedstep-ich to actually enable frequency scaling. The cpufreq
documentation says SOME PIII Coppermine processors will work but not
all. Is this one of the ones that has the primitive Speeedstep, in that
you can choose normal operating mode or power saving mode in the BIOS
and that's it? Because I tried the one that's optimized for battery life
and it does little to help. My battery life is about 4 hours but there
are still plenty of extra timer interrupts. If this is one of the
Coppermines that can use cpufreq, there must be some trick to setting it
up, because I can't figure it out.
Also, I don't think the system board has an HPET timer. I tried setting
the clock=hpet kernel parameter but there were just as many extra timer
interrupts as before, so I think it ignored the parameter and used
clock=pit again.
I'm willing to accept that my laptop is just too old to be efficient,
but if there is some way to make it more efficient that I haven't
thought of, could you tell me? Thanks.