cpu frequency falling to its lower value causes system to pause

(In reply to comment #0)
I have tried the LEAPS profile to no effect. I wonder if it has to do with the
frequency scaling daemon trying to use intermediate frequencies between the
highest and lowest, which does not exist on the Pentium M 1.13 GHz.

(In reply to comment #0)
> I have experienced this problem with my Dell Latitude 810 laptop (Pentium M 1.13
> GHz) since Hoary was installed a few weeks ago. The machine pauses for a second
> or two every time the cpu frequency falls to its lower value. This did not occur
> when using Fedora Core 3, which uses cpuspeed. I have tried cpuspeed on Ubuntu
> but I still get the pauses. cpudyn and cpufreqd also exhibit the behaviour. This
> leads me to believe it may not be powernowd but the cpufreq subsystem itself.

This also occurs on an Acer TravelMate C100 that steps between two speeds -
400MHz and 800MHz. It also causes me to lose characters at terminals :| If the
behaviour cannot be substantially improved, I hope powernowd will NOT be enabled
by default on the forthcoming release.

I can confirm this behaviour on a dell inspiron 8100 with Pentium 3 Mobile 1.13 GHz.
When throttling down to from 1.13 GHz to 731 MHz there is a half second
complete freeze of everything. Really annoying.

Anybody with this problem tried using a vanilla kernel?

I've been struggling with this for a long time now. (See my log on
http://www.ii.uib.no/~ketil/ubuntu-prob.log ). Note that my self-compiled
kernel with low-latency patches (which works correctly) doesn't do frequency
scaling, but I'll recompile and try it when I get the time.

Dell Latitude C810 (P3 1.13)

Compiled 2.6.11.7 from kernel.org, the problem persists.

My current "solution" is to set the "governor" to something else
than userspace, e.g.:

  # echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

Which seems to keep my system at its high CPU frequency setting.

Is this problem something kernel developers and/or Ubuntu know about
and are going to fix?

As of this posting, I am now not experiencing this bug. I have no idea when the
pause ceased to manifest itself. My current kernel is:

seymour@bentley$ uname -a
Linux bentley 2.6.10-5-686 #1 Tue Jun 7 09:00:32 UTC 2005 i686 GNU/Linux

I think this bug can be considered closed.

Sorry that I cannot supply whne the bug was fixed. When things work as expected,
these issues tend to be forgotten.

The bug disappeared for me too, but when I reinstalled with Breezy (beta), it
reappeared. As this is pretty annoying behavior, I think frequency scaling
should be disabled (for a known set of laptop hardware? All Pentium IIIs?)
until its cause can be determined.