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

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

User visible changes:

  - Adding a field via 'perf report -F' that already is enabled makes
    the tool get stuck in a loop, fix it. (Jiri Olsa)

Infrastructure changes:

  - Support PERF_RECORD_SWITCH in the python binding. (Arnaldo Carvalho de Melo)

  - Fix handling read() result using a signed variable, found with Coccinelle.
    (Andrzej Hajda)

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