Wind River Support Network

HomeDefectsLIN7-775

Not to be fixed

LIN7-775 : Many [UNMAPPED] entries in Profiler, due to last address in perf callchain is unmappable

Created: Sep 5, 2014 Updated: Mar 4, 2016

Resolved Date: Dec 9, 2014

Previous ID: WB4-4145

Found In Version: 7.0

Severity: Standard

Applicable for: Wind River Linux 7

Component/s: Analysis

Description

In the Workbench Memory Analyzer or Profiler, the toplevel node is [UNMAPPED] in many cases when viewing results top-down. This causes confusion with users.

Steps to Reproduce

The following steps demonstrate that perf itself is the culprit for not resolving the bottom frame of the calltree in many cases:

1) Record some callchains using
    perf record -g -- python -c "2**2**25"
2) Display callchains
    perf script

-->
The last address in the perf callchain is usually not mappable to any shared object or executable.

E.g.
7f8e2cbb0785 Py_Initialize (/usr/lib64/libpython2.7.so.1.0)
7f8e2cbbe189 Py_Main (/usr/lib64/libpython2.7.so.1.0)
4007db main (/usr/bin/python2.7)
3c02a20010 __libc_start_main (/lib64/libc-2.19.so)
ec83485354415541 [unknown] ([unknown])