[ltt-dev] "ust_3 does not contain a trace" and subsequent "segfault at 10 ip b770632f sp bf864290 error 4 in liblttvtraceread-2.6.so[b7704

[Mathieu Desnoyers]

* Lior Assouline (Lior.Assouline at harmonicinc.com) wrote:
> Hi,
> I'm running my program using "usttrace -o ~/trace1 ./prog" and later
> on trying to see the traces using
> 
> "lttv -L /usr/local/lib/lttv/plugins -m textDump --trace ~/trace1/"
> 
> and getting the following output
> 
> lior at lior-linux-desktop:~/devel/lior_branch$ lttv -L /usr/local/lib/lttv/plugins -m textDump --trace ~/trace1/23195_167510/
> The input data file /home/lior/trace1/23195_167510/ust_3 does not contain a trace
> The input data file /home/lior/trace1/23195_167510/ust_1 does not contain a trace
> The input data file /home/lior/trace1/23195_167510/ust_2 does not contain a trace
> The input data file /home/lior/trace1/23195_167510/metadata_0 does not contain a trace
> The input data file /home/lior/trace1/23195_167510/metadata_1 does not contain a trace
> The input data file /home/lior/trace1/23195_167510/metadata_2 does not contain a trace
> The input data file /home/lior/trace1/23195_167510/ust_0 does not contain a trace
> /usr/local/bin/lttv: line 15: 23354 Segmentation fault $0.real "$@"
> lior at lior-linux-desktop:~/devel/lior_branch$
> lior at lior-linux-desktop:~/devel/lior_branch$ sudo dmesg -c
> [ 6909.533315] lttv.real[23354]: segfault at 10 ip b770632f sp bf864290 error 4 in liblttvtraceread-2.6.so[b7704000+8000]
> 
> looking at the trace dir:
> 
> lior at lior-linux-desktop:~/devel/lior_branch$ ls -la ~/trace1/23195_167510/
> total 12
> drwxr-xr-x 2 lior lior 4096 2011-10-09 14:27 .
> drwxr-xr-x 4 lior lior 4096 2011-10-09 14:29 ..
> -rw------- 1 lior lior 0 2011-10-09 14:27 metadata_0
> -rw------- 1 lior lior 0 2011-10-09 14:27 metadata_1
> -rw------- 1 lior lior 0 2011-10-09 14:27 metadata_2
> -rw------- 1 lior lior 4096 2011-10-09 14:27 metadata_3
> -rw------- 1 lior lior 0 2011-10-09 14:27 ust_0
> -rw------- 1 lior lior 0 2011-10-09 14:27 ust_1
> -rw------- 1 lior lior 0 2011-10-09 14:27 ust_2
> -rw------- 1 lior lior 0 2011-10-09 14:27 ust_3
> 
> Any idea how to move on ?

0-sized files is definitely not good. It looks like the consumer could
not extract the buffers.

Is your program short-lived ? Adding a sleep of 1-2 seconds before it
exits might help. This UST 0.x design issue will be resolved in UST 2.0

Is your program still running ? The UST 0.x consumer cannot extract the
last buffers until the program exits.

Best regards,

Mathieu

> 
> Thanks
> Lior
> 

> _______________________________________________
> ltt-dev mailing list
> ltt-dev at lists.casi.polymtl.ca
> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev


-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com