[Asterisk-Users] Interrupt latency problems

[Michael Welter]

I'm debugging a TxFax problem whereby the fax transmission fails.  I 
suspect interrupt latency--some interrupt routine is holding its 
interrupt too long.  I have all unnecessary services switched off and X 
is not running when I perform these tests.  Some transmission are 
successful while others fail at random points.

I've noticed that after I boot Linux, load zaptel, wcfxo, and wcfxs, and 
then run System Monitor, the CPU utilization spikes to 60% every 10 
seconds.  After I remove wcfxs the spikes stop, and system utilization 
stays at 0%.

I have two TDM22B cards and get these spikes with either card in the system.

This is an Athlon-64 3000+ CPU and Fedora Core 2.  zaptel-1.0.2.

Is there anyone who has a TDM card on a "quiet" system who can run 
System Monitor and observe CPU utilization?

Thanks for your help.

P.S.  I do 'hdparm -u1 /dev/hdx' on the disks.


-- 
Michael Welter
Introspect Telephony Corp.
Denver, Colorado US
+1.303.674.2575
mike at introspect.com
www.introspect.com