Merge tag 'perf-urgent-for-mingo-5.7-20200403' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

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

perf python:

  Arnaldo Carvalho de Melo:

  - Fix clang detection to strip out options passed in $CC.

build:

  He Zhe:

  - Normalize gcc parameter when generating arch errno table, fixing
    the build by removing options from $(CC).

  Sam Lunt:

  - Support Python 3.8+ in Makefile.

perf report/top:

  Arnaldo Carvalho de Melo:

  - Fix title line formatting.

perf script:

  Andreas Gerstmayr:

  - Fix SEGFAULT when using DWARF mode.

  - Fix invalid read of directory entry after closedir(), found with valgrind.

  Hagen Paul Pfeifer:

  - Introduce --deltatime option.

  Stephane Eranian:

  - Allow --symbol to accept hexadecimal addresses.

  Ian Rogers:

  - Add -S/--symbols documentation

  Namhyung Kim:

  - Add --show-cgroup-events option.

perf python:

  Arnaldo Carvalho de Melo:

  - Include rwsem.c in the python binding, needed by the cgroups improvements.

build-test:

  Arnaldo Carvalho de Melo:

  - Honour JOBS to override detection of number of cores

perf top:

  Jin Yao:

  - Support --group-sort-idx to change the sort order

  - perf top: Support hotkey to change sort order

perf pmu-events x86:

  Jin Yao:

  - Use CPU_CLK_UNHALTED.THREAD in Kernel_Utilization metric

perf symbols arm64:

  Kemeng Shi:

  - Fix arm64 gap between kernel start and module end

kernel perf subsystem:

  Namhyung Kim:

  - Add PERF_RECORD_CGROUP event and Add PERF_SAMPLE_CGROUP feature,
    to allow cgroup tracking, saving a link between cgroup path and
    its id number.

perf cgroup:

  Namhyung Kim:

  - Maintain cgroup hierarchy.

perf report:

  Namhyung Kim:

  - Add 'cgroup' sort key.

perf record:

  Namhyung Kim:

  - Support synthesizing cgroup events for pre-existing cgroups.

  - Add --all-cgroups option

Documentation:

  Tony Jones:

  - Update docs regarding kernel/user space unwinding.

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

init/Kconfig

@@ -1030,7 +1030,8 @@ config CGROUP_PERF
 	help
 	  This option extends the perf per-cpu mode to restrict monitoring
 	  to threads which belong to the cgroup specified and run on the
-	  designated cpu.
+	  designated cpu.  Or this can be used to have cgroup ID in samples
+	  so that it can monitor performance events among cgroups.
 
 	  Say N if unsure.