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Bug #1181

Updated by Francis Deslauriers about 2 years ago

I encountered a deadlock of the session daemon when tracing short lived UST app in burst. I was not able to reproduce it. 
 Here is the session configuration: 
 <pre> 
 lttng create allo --live 
 lttng enable-channel --buffers-pid -s allo --tracefile-size=5M --tracefile-count=4 -u chan1 
 lttng enable-event -u -a -c chan1 
 lttng start allo 
 </pre> 
 After configured this session, I ran the following for loop followed by a lttng destroy command. As such: 
 <pre> 
 for i in `seq 1 1`; do 
    ../../../lttng-emojis/main & ; 
 done; 
 lttng destroy -a 
 </pre> 
 These apps run and exit very quickly. *The lttng destroy command never completes* . 

 I attached the source code of the app as well as the backtraces of both lttng session daemon and the lttng consumer daemon. 

 We gathered so far: 
 sessiond thread 8: waiting on consumer socket (recv), while holding the consumer socket lock 
 sessiond thread 11: waiting for socket lock, while holding ust registry lock 
 sessiond thread 15: waiting for ust registry lock 

 consumerd thread 4: waiting for stream lock 
 consumerd thread 7: waiting on consumer metadata socket(recv), while holding stream lock 
 consumerd thread 8: waiting for stream lock 

 I was running this lttng-tools branch: https://github.com/PSRCode/lttng-tools/tree/live-per-pid (commit f0e3b9ebe) 


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