High CPU - kjournald & kblockd

[Brian Hanks]

Has anyone else experienced what I will call sporadic, jerky X response
in FC2?  It seems that any time I have a background process running that
is even remotely utilizing any CPU or IO, I have pathetic response in
X.  

My RH9 box and my FC1 box don't have this issue and they are slower
machines with less memory and older disk.  As a test to rule out CPU or
chipset specific issues, I've built a completely different machine with
FC2.  Both machines exhibited the exact same behavior. 

I quite reluctant to make the switch to FC2 without solving this issue. 
It's quite annoying to have X become unstable every time I go to compile
something in the background.  

Hardware Setup #1:
Asus A7V600 (VIA Chipset)
1 GB RAM
Athlon XP 3000+
2 Samsung 120 GB SATA drives (RAID1 with LVM2)
NVIDIA MX440
FC2 fully updated

Hardware Setup #2:
Asus A7N266-VM (NVidia Chipset)
1 GB RAM
Athlon XP 2100+
2 Maxtor 40 GB ATA drives (RAID1 with LVM2)
NVIDIA MX400
FC2 fully updated

Upon further digging, it looks like kblockd & kjournald
are chewing up a ton of CPU.  I'm even noticing it when I don't have
large processes running.  It's definitely not as severe, but it seems to
be occurring quite regularly. 

The one test that I haven't done is to remove LVM2 and RAID1 from the
picture.  I wonder if that would eliminate the problem?

What exactly is the function of kblockd and kjournald?  Any insight
would be greatly appreciated.

Thanks,
Brian Hanks
bhanks at bhanks.com