[Discuss] Very slow system, no idle, but nothing running

[David Kramer]

This is on my Ubuntu 10.04 laptop (Dell Latitude D820).  I don't know
when it started, but every now and then I get into this condition where
the UI seems almost completely locked up (the mouse may move a little
occasionally  but the clock is frozen).  The hard drive light is often
on for long periods of time, too.  But even when I can move the mouse,
clicking on a window's close button does nothing.  Usually it never
recovers from this state and I need to hard power down.

The first couple of line from "top -c" read
top - 00:13:25 up 6 days, 16:25,  6 users,  load average: 16.16, 19.67,
21.58
Tasks: 194 total,   3 running, 189 sleeping,   0 stopped,   2 zombie
Cpu(s): 13.3%us,  5.0%sy,  0.0%ni,  0.0%id, 81.4%wa,  0.2%hi,  0.2%si,
0.0%st
Mem:   2060180k total,  2009288k used,    50892k free,     3488k buffers
Swap:  1574328k total,  1492652k used,    81676k free,    62024k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND

 6835 david     20   0  704m 184m 2352 R   20  9.2 142:15.54
plugin-containe
19747 david     20   0  226m 170m 4868 S   15  8.5   4:07.80 geeqie

 1185 root      20   0  231m  82m 6488 S    1  4.1 137:38.82 Xorg

 6637 david     20   0 1174m 264m  11m D    1 13.2  99:02.16 firefox

20780 root      20   0  2548 1240  916 R    1  0.1   0:00.04 top

    9 root      20   0     0    0    0 S    0  0.0   0:05.28 events/0


So I don't see what the cores are so busy with. I was only able to get
these numbers by eventually getting a text mode screen by pressing
Ctr-Alt-F2 (get to a text shell) before it decided to do something.
Swap space is low but should be sufficient.

What can be locking up my laptop and causing the slowdown?

Thanks.