[SRU][Bionic][Cosmic][PATCH 0/1] Fix for perf top problem on s390x (LP: #1828166)

[Kleber Sacilotto de Souza]

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

[Impact]

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

[Fix]

* edeb0c90df3581b821a764052d185df985f8b8dc edeb0c9 "perf tools: Stop
  fallbacking to kallsyms for vdso symbols lookup"
* The patch can be cleany applied to Cosmic but needed a simple
  backport for Bionic for context adjustment.

[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 low since this
  happens only while using the perf top tool
* and it is known that the commit (above) fixes the problem
* and the fix is upstream since 4.19

Arnaldo Carvalho de Melo (1):
  perf tools: Stop fallbacking to kallsyms for vdso symbols lookup

 tools/perf/util/event.c | 21 ++-------------------
 1 file changed, 2 insertions(+), 19 deletions(-)

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2.17.1