[asterisk-bugs] [Asterisk 0014625]: Random deadlocks leading to lockup on 1.4.23.1

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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http://bugs.digium.com/view.php?id=14625 
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Reported By:                acunningham
Assigned To:                
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Project:                    Asterisk
Issue ID:                   14625
Category:                   General
Reproducibility:            random
Severity:                   major
Priority:                   normal
Status:                     acknowledged
Asterisk Version:           1.4.23 
Regression:                 No 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
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Date Submitted:             2009-03-08 19:36 CDT
Last Modified:              2009-03-24 17:55 CDT
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Summary:                    Random deadlocks leading to lockup on 1.4.23.1
Description: 
Random channels seem to be giving deadlocks on a 1.4.23.1 system:

# tail -f /var/log/asterisk/full | grep -i deadlock
[Mar  8 20:35:37] DEBUG[4249] channel.c: Avoiding initial deadlock for
channel '0x8779688'
[Mar  8 20:35:37] DEBUG[4249] channel.c: Avoiding initial deadlock for
channel '0x87ff698'
[Mar  8 20:35:42] DEBUG[4249] channel.c: Avoiding initial deadlock for
channel '0x8314468'
[Mar  8 20:35:46] DEBUG[4249] channel.c: Avoiding initial deadlock for
channel '0x861ddd0'


I've also seen "Avoiding deadlock" as well as "Avoiding initial deadlock",
though these are less common. The system is continually busy at medium load
(tens of calls). Over a period of days, the problem gets worse and worse
until Asterisk stops handling calls and needs to be killed with "kill -9".
Compiling with DEBUG_THREADS and running "core show locks" always shows:

=======================================================================
=== Currently Held Locks ==============================================
=======================================================================
===
=== <file> <line num> <function> <lock name> <lock addr> (times locked)
===
=======================================================================

with no further output. I've tried the patch in ticket
http://bugs.digium.com/view.php?id=13116 but this
doesn't help.

I'm not sure what debugs would be useful, but if someone can advise what
would be useful I'm happy to take them.
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 (0102146) acunningham (reporter) - 2009-03-24 17:55
 http://bugs.digium.com/view.php?id=14625#c102146 
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Thank you for the prompt follow-up.

We can't actually tell how many calls there were as we were unable to
connect to the console, but at that time time of day there are typically
between 5 and 20 calls.

All calls are processed using FastAGI after a little manipulation of
called/calling numbers in extensions.conf.

We already have the following set in /etc/security/limits.conf:

* hard nofile 65535
* soft nofile 65535
* hard nproc 65535
* soft nproc 65535

so I don't think we can increase the number of file descriptors beyond
what's already set. 

Issue History 
Date Modified    Username       Field                    Change               
====================================================================== 
2009-03-24 17:55 acunningham    Note Added: 0102146                          
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