[asterisk-bugs] [Asterisk 0019078]: pri lockup. no futher calls able to be taken

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=19078 
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Reported By:                alecdavis
Assigned To:                
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Project:                    Asterisk
Issue ID:                   19078
Category:                   Channels/chan_dahdi
Reproducibility:            sometimes
Severity:                   minor
Priority:                   normal
Status:                     feedback
Asterisk Version:           1.8.2.3 
JIRA:                        
Regression:                 No 
Reviewboard Link:            
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
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Date Submitted:             2011-04-06 22:00 CDT
Last Modified:              2011-04-07 17:45 CDT
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Summary:                    pri lockup. no futher calls able to be taken
Description: 
attached backtrace and core show locks
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 (0133521) rmudgett (administrator) - 2011-04-07 17:45
 https://issues.asterisk.org/view.php?id=19078#c133521 
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The particular deadlock in core-show-locks.txt doesn't make sense to me.  I
think the holder of the private lock should not still have it.  It looks
like someone also tried a pri_grab() without already having the private
lock based upon your ERROR messages above.

The deadlock issue I ran into was because the private lock was held by
pri_dchannel() while it was trying to create the ast_channel for an
incoming call.

Part of the B channel shifting patch added channel allocation protection
between incoming and outgoing calls picking the same B channel.  See
sig_pri_available() and sig_pri_is_chan_available().

B channel shifting patch is -r312575 and -r312949 for v1.8.

What is the call pattern for this particular box?
Is it in/out calls?
Is it very busy?

Collision mitigation may be possible by using a different channel
allocation strategy to avoid both sides being likely to pick the same B
channel. 

Issue History 
Date Modified    Username       Field                    Change               
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2011-04-07 17:45 rmudgett       Note Added: 0133521                          
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