[SRU][Bionic][Disco][PATCH 0/2] Fix for perf top problem on s390x (LP: #1828166)

Kleber Sacilotto de Souza kleber.souza at canonical.com
Fri Aug 23 12:07:15 UTC 2019

BugLink: https://bugs.launchpad.net/bugs/1828166


* The perf top tool hangs and shows error messages, like 'Not enough
memory for annotating'


The following fixes have been developed by IBM and accepted upstream:

* b9c0a64901d5bdec6eafd38d1dc8fa0e2974fccb b9c0a64 "perf annotate: Fix
s390 gap between kernel end and module start"

* 12a6d2940b5f02b4b9f71ce098e3bb02bc24a9ea 12a6d29 "perf record: Fix
module size on s390"

Disco needs also as prereq:

* 6738028dd57df064b969d8392c943ef3b3ae705d 6738028 perf record: Fix i
s390 missing module symbol and warning for non-root users

These fixes are either cherry picked or required small context

[Test Case]

* start a benchmark (mem_alloc, but it doesn't really matter what)

* execute perf top in a second terminal

* the output of perf top is correct

* now stop the benchmark

* and perf top shows an error message, like "Not enough memory for
annotating '__irf_end' symbol!)"

* and perf top can't be exited anymore

[Regression Potential]

* The regression potential can be considered as medium since this
happens only while using the perf top tool and just 3 files are
changed, and one of them is arch/s390/util/machine.c. But symbol
and machine header in /tools/perf/util modified and several
loc added.

* Smoke tested 'perf top' for regressions on a amd64 VM, no issues

[Additional Info]

These patches have already been committed to Eoan (LP: #1841110).

Thomas Richter (2):
  perf record: Fix module size on s390
  perf annotate: Fix s390 gap between kernel end and module start

 tools/perf/arch/s390/util/machine.c | 31 ++++++++++++++++++++++++++++-
 tools/perf/util/machine.c           |  3 ++-
 tools/perf/util/machine.h           |  2 +-
 tools/perf/util/symbol.c            |  7 ++++++-
 tools/perf/util/symbol.h            |  1 +
 5 files changed, 40 insertions(+), 4 deletions(-)


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