Repeated slowdowns in 2.4.17

My laptop, Duron 900MHz, 384MB RAM, running linux 2.4.17 with
preempt and ide patches, occasionally gets into an odd state
where each process only gets a tiny bit of CPU time every 7
seconds.  My laptop had been running for 10 minutes, and I
had up to this point run nothing unusual.

In an rxvt for example, type a few characters, and they show up
about 7 seconds later.  The delay isn't always 7 seconds.
The rxvt seems to be getting a bit of CPU every 7 seconds.
So if you type your characters just as the "slice" of
time is coming up they show up right away.

I got top running, and nothing unusual was happening.  swap
empty. top updating the screen every 7 seconds, eventhrough
it was set to 1 second update.

updatedb was running, and may have been what started the problem.
[guessing] I waited patiently and even after updatedb finished the 
system was still in the odd state.

I started killing things: lvcool, mozilla.  Nothing helped.

The system seemed to work, just with each process getting a
tiny bit of CPU every 7 seconds.

This problem occured before I added the ide patch.

While updatedb was running disk io seemed to be running full speed.

The X cursor moved on the screen fine, and I could switch
desktops (WindowMaker) instantly, but the processes that were to
fill in the screen were running in the 7 second mode.

I started a new rxvt and it showed up about 2 minutes later.

I ran poweroff and about 3 minutes later the system powered down.

Mouse/Keyboard events seemed to be instant so far as X was concerned.
Everywhere else they experienced the 7 second delay.

The problem occurs maybe once a week.  If anyone wants to suggest
that I try something the next time this occurs let me know.

-- 
Brian Litzinger <[e-mail]>

    Copyright (c) 2002 By Brian Litzinger, All Rights Reserved