Tracer appears to be hung due to taking too much time.

Customer provided some data for debugging the issue.

Based on some strace, perf and cProfile data, we can see that the bottleneck
appears to be the regex split code. In a very short run, to profile a bit, it
is called almost 2 million times, and using more than 90% of the processing
time.

Sample cProfile output:

ncalls tottime percall cumtime percall filename:lineno(function)
1745231 413.627 0.000 413.627 0.000

{method 'split' of '_sre.SRE_Pattern' objects}

9175435 35.478 0.000 473.426 0.000 /usr/lib/python3.6/site-packages/tracer/resources/processes.py:76(name)
1746812 17.331 0.000 17.332 0.000

{method 'join' of 'str' objects}

23604269 4.621 0.000 4.621 0.000 /usr/lib/python3.6/site-packages/tracer/resources/processes.py:114(_attr)
4362 3.370 0.001 3.371 0.001

{method 'send_message_with_reply_and_block' of '_dbus_bindings.Connection' objects}

164719 3.258 0.000 4.943 0.000 /usr/lib64/python3.6/site-packages/psutil/_pslinux.py:1800(get_blocks)
1510 2.475 0.002 4.500 0.003

{method 'block' of 'dbus.lowlevel.PendingCall' objects}

3058071 2.466 0.000 478.441 0.000 /usr/lib/python3.6/site-packages/tracer/resources/applications.py:272(<lambda>)
2294 2.111 0.001 2.111 0.001

{built-in method posix.listdir}

3058071 1.617 0.000 317.814 0.000 /usr/lib/python3.6/site-packages/tracer/resources/processes.py:276(real_name)
1512 1.560 0.001 1.968 0.001

{method 'Parse' of 'pyexpat.xmlparser' objects}

3935101 1.324 0.000 1.324 0.000

{method 'split' of 'bytes' objects}

2281 1.206 0.001 6.560 0.003 /usr/lib/python3.6/site-packages/tracer/resources/processes.py:41(all)