Strange pauses and cpu usage - FreeBSD 6.1

[Chuck Swiger]

Shawn wrote:
> I'm having a strange problem with cpu usage with my Athlon XP. Every so
> often there seems to be a pause where the system comes under heavy
> load for no apparent reason. If xmms was playing then I get a buzz sound
> and the mouse pointer stops just for a split second, the same with
> mplayer and vlc. Using Opera or firefox also seems to have a strange
> effect where the mouse pointer freezes while pages load, and if there
> is an animated gif on the page the cpu usage goes to 100%.
>
> The jabber client Gajim also makes the cpu get stuck at 100%. When I
> used gnome, nautilus did the same thing until i stopped and started the
> process in the system monitor. I have searched around and found this
> tip from the handbook but it had no effect.

To some extent, that kind of behavior is normal for FreeBSD and most 
other systems which do not make hard or soft real-time guarantees.  
However, there may also be things you can do to improve the situation or 
a legitimate problem to be fixed as well...having the mouse pointer 
freeze implies that interrupts were being blocked or at least the 
Xserver was.  If you're using USB devices, try using a PS/2 mouse 
instead and see whether that makes any difference.

Is the system OK with memory, or are you running low enough to page out 
X, perhaps?  Check top & "vmstat -s".
Try increasing the amount of buffer space available to the PCM or 
whatever sound card driver you're using (there's a sysctl or loader.conf 
setting which I forget, but it probably googles)...

-- 
-Chuck