[asterisk-bugs] [Zaptel 0011188]: CPU load spikes every 10 seconds

[noreply at bugs.digium.com]

A NOTE has been added to this issue. 
====================================================================== 
http://bugs.digium.com/view.php?id=11188 
====================================================================== 
Reported By:                dimas
Assigned To:                mattf
====================================================================== 
Project:                    Zaptel
Issue ID:                   11188
Category:                   wctdm24xxp
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     assigned
Zaptel Version:              SVN 
SVN Branch (only for SVN checkouts, not tarball releases):  1.4  
SVN Revision (number only!): 3220 
Disclaimer on File?:        N/A 
Request Review:              
====================================================================== 
Date Submitted:             11-07-2007 16:17 CST
Last Modified:              03-20-2008 14:47 CDT
====================================================================== 
Summary:                    CPU load spikes every 10 seconds
Description: 
While running 'top' I noticed that approximately every 10 seconds "%hi"
(hardware interrupt) CPU load jumps to about 30-60%. See Additional
Information for vmstat output.

I have TDM2400 with 2xFXO and 1xFXS module. CentOS 5 running at Intel(R)
Pentium(R) 4 CPU 1.90GHz stepping 02.

What I found out:
1. executing "modprobe -r wctdm24xxp" heals problem - spikes disappear.
But obviously I left without Zap channels in this case. 
2. spikes are present regardless if Asterisk is running or not
3. I also checked checked Zaptel 1.4.4, 1.4.6 - all demonstrate the same
behavior.
4. The system is not busy with processing any calls when these spices
occur. Basically the system is idle.

Corydon suggested me to contact support regarding this problem as they may
want to replace the whole card. Unfortunately it can take a lot of time in
my case. So first I would like to get some evidences if it is hardware or
software problem. 
Please let me know how can I collect any debugging information which could
help.
====================================================================== 

---------------------------------------------------------------------- 
 sruffell - 03-20-08 14:47  
---------------------------------------------------------------------- 
For what it's worth, I've seen this too with the TDM24xxp on CentOS 5 with
a 2.6.18 kernel.  

My current operating hypothesis is that it is a problem in how the load
averages are computed given the amount of work the driver does in interrupt
context. 

Issue History 
Date Modified   Username       Field                    Change               
====================================================================== 
03-20-08 14:47  sruffell       Note Added: 0084357                          
======================================================================