Merge tag 'perf-core-for-mingo-20160715' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

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

User visible changes:

 - Allow reading from a backward ring buffer (one setup via sys_perf_event_open()
   with perf_event_attr.write_backward = 1) (Wang Nan)

Infrastructure changes:

 - Fix the build on Android NDK r12b (initially just for ARM), that is now port
   of my perf-build container collection and will get tested prior to sending
   patches upstream (Arnaldo Carvalho de Melo)

 - Add correct header for IPv6 definitions

 - Fix bitsperlong.h fallout (Arnaldo Carvalho de Melo, Peter Zijlstra)

 - Use base 0 (auto) in filename__read_ull(), so that we can handle hex values too (Jiri Olsa)

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