[Asterisk-Users] Interrupt latency problems

Steve Clark sclark at netwolves.com
Wed Dec 1 11:16:06 MST 2004


Michael Welter wrote:
> 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.
> 
> 

Forget what I just posted - after watching top for a while about every 30 
seconds I see irq% go to about 30%.

Steve

-- 

"They that give up essential liberty to obtain temporary safety,
deserve neither liberty nor safety."  (Ben Franklin)

"The course of history shows that as a government grows, liberty
decreases."  (Thomas Jefferson)





More information about the asterisk-users mailing list