[asterisk-bugs] [Asterisk 0010775]: Asterisk suddenly slows down, and eats 100% cpu

[noreply at bugs.digium.com]

A NOTE has been added to this issue. 
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http://bugs.digium.com/view.php?id=10775 
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Reported By:                atis
Assigned To:                
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Project:                    Asterisk
Issue ID:                   10775
Category:                   Core-General
Reproducibility:            random
Severity:                   major
Priority:                   normal
Status:                     new
Asterisk Version:            1.4.10  
SVN Branch (only for SVN checkouts, not tarball releases): N/A  
SVN Revision (number only!):  
Disclaimer on File?:        N/A 
Request Review:              
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Date Submitted:             09-20-2007 16:36 CDT
Last Modified:              09-24-2007 04:53 CDT
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Summary:                    Asterisk suddenly slows down, and eats 100% cpu
Description: 
I'm running 1.4.10 (with reverted res_features from
http://bugs.digium.com/view.php?id=10415). Approximately
once or twice per week (restarted daily) asterisk suddenly starts acting
slowly, and eats 100% cpu. Call volume drops as it takes really long time
for customers to get to agents, but this doesn't improve situation in any
way.

Last week i recompiled with DONT_OPTIMIZE, DEBUG_THREADS and DEBUG_LOCKS,
so now i can attach debug output.

I killed asterisk with "killall -5 asterisk", so that core is dumped.

Attached files:
backtrace.txt - backtraces taken from core

report.txt - various information ("top", "core show threads", "core show
locks", "core show channels") right before i killed asterisk.

normal.txt - top, and channel count when under normal load (30 minutes
after kill)

cli.txt - multiple consecutive executions of "core show threads" and "core
show locks", when problem raised.


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---------------------------------------------------------------------- 
 atis - 09-24-07 04:53  
---------------------------------------------------------------------- 
Ok, i digged into sources and found that it's all related to last lines of
code in main/asterisk.c. There's infinite loop "for(;;)", that reads
something from console. I don't know what have caused this - i double
checked all my system looking for tty9, there's nothing that could have
caused it. As temporary solution - i disabled console in safe_asterisk (and
would recommend to do so in  distribution). 

However the problem is somewhere there, i'm just not enough familiar with
code to find it.Maybe because of "num_read", that i suppose means
characters read? Why it's 5 megabytes? Could this slow down everything?
Note, that it's the same value in all 3 backtraces.

http://bugs.digium.com/view.php?id=1  0x00000000004db0d7 in read_char
(el=0x96ac70, cp=0x7fffc6d954c6 "") at
read.c:296^
  num_read = 5116828^
  tried = 0^ 

Issue History 
Date Modified   Username       Field                    Change               
====================================================================== 
09-24-07 04:53  atis           Note Added: 0071023                          
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