BUG(?): kswapd eating CPU

[achurch@achurch.org (Andrew Church)]

     I just had a strange case where kswapd started eating up 100% CPU
time.  I haven't been able to reproduce it, but it seemed to occur when I
did a "dd bs=4096 </dev/fb0 >/scratch/image" in X while writing a CD (4x)
from the same filesystem--the dd took 10-20 times longer than usual, and
kswapd's run time from ps also pointed to the same time.  At the time,
roughly 6MB of real memory was free, but most in-use memory (~800MB) was
cached data; only 3MB or so of swap was used.  The system itself seemed to
remain stable, though I rebooted shortly after I discovered the problem.

     System is as follows: (if more info is desired, please contact me
directly at achurch@achurch.org--I'm not subscribed to the list)

Kernel: 2.4.13 (i686, SMP)
CPU   : Dual Pentium II 400MHz
Memory: 896MB RAM, 576MB swap
IDE   : 1 HD (data, including /scratch, and 512MB swap)
SCSI  : 1 HD (root and 64MB swap), 1 CD-R drive
Video : 3dfx Voodoo 3 (PCI), 16MB VRAM (3dfx framebuffer driver enabled
	for virtual consoles, but X hits the hardware directly)

  --Andrew Church
    achurch@achurch.org
    http://achurch.org/