[ltp] Ubuntu 6.06 Xorg cpu usage spikes

[Daniel Skorka]

On Wed, Nov 15, 2006 at 10:40:59AM -0500, nate wrote:
> I don't know where else to look, but lately Ubuntu 6.06 has been acting
> up on my laptop. Most things I can live with- having to run 'pmi action
> sleep' to suspend, my wireless card sometimes being lost on wake from
> suspend (rmmod, then modprobe ipw2100), evolution being slow to
> recognize a new wireless connection (xkill and re-open), firefox
> freezing on some websites (they're probably not standards compliant
> anyway).

The first two can be easily automated by using acpid with a script in
/etc/acpi
Your problems with evolution and firefox seem more likely to be
application bugs.

> But recently after using the computer for a while (24 hours current
> uptime) Xorg starts to use lots of cpu. Usually the first thing I notice
> is my mouse stutters or scrolling line by line up/down in vim will be
> much slower. Then whenever I do the most trivial task, like moving a
> console window around, the window will jerk or stutter as it's moving
> and cpu usage goes up to about 90%. What can fix it is restarting gdm.

I have the same problem (I think [using Xorg 6.9.0 here]). It is a bug
in Xorg triggered by logrotate rotating /var/log/acpid. In doing this,
it restarts acpid which results in /var/run/acpid.socket being
recreated.  Xorg doesn't like that, and spends all the time it can get
in trying to reopen a no longer existing socket.  When you restart Xorg,
it opens the new socket and everything is well again.
Workaround: Don't rotate /var/log/acpid, at least not when X11 is
running.
Fix: Install a version of Xorg that is not affected.

> I can't identify any changes that I made to the system that caused it to
> start doing this. I've been using this install for a few months without
> this problem.

I bet you did some 'apt-get update's in the meantime :)

> I must not be the only person with this problem, and I bet there is a
> forum post about it somewhere, but I can't find it. Can anyone point me
> to something that might help?

Just google for something like 'xorg acpi bug', better yet search the
Xorg bugzilla.

Daniel
-- 
'strip' ist ein tolles Programm, egal ob man ein paar MB Plattenplatz mehr
haben oder seine X11 Installation ruinieren will.
        -- "Lernen auf die harte Tour", Nr. 87