Merge tag 'perf-core-for-mingo-4.17-20180328' of git://git.kernel.org/pub/scm/linux...

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

- Be consistent when checking if a perf_mmap instance had
  its ring buffer unmmaped, fixing segfaults noticed in
  'perf trace' (Kan Liang, Arnaldo Carvalho de Melo)

- Avoid adding the same option multiple times to the 'diff'
  command in check-headers.sh (Jiri Olsa)

- Add vendor event files (JSON format) to various IBM
  s390 models (z10EC, z10BC, z196, zEC12, zBC12, z13
  and z14) (Thomas Richter)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>