Merge tag 'perf-urgent-2020-04-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull more perf updates from Thomas Gleixner:
 "Perf updates all over the place:

  core:

   - Support for cgroup tracking in samples to allow cgroup based
     analysis

  tools:

   - Support for cgroup analysis

   - Commandline option and hotkey for perf top to change the sort order

   - A set of fixes all over the place

   - Various build system related improvements

   - Updates of the X86 pmu event JSON data

   - Documentation updates"

* tag 'perf-urgent-2020-04-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (55 commits)
  perf python: Fix clang detection to strip out options passed in $CC
  perf tools: Support Python 3.8+ in Makefile
  perf script: Fix invalid read of directory entry after closedir()
  perf script report: Fix SEGFAULT when using DWARF mode
  perf script: add -S/--symbols documentation
  perf pmu-events x86: Use CPU_CLK_UNHALTED.THREAD in Kernel_Utilization metric
  perf events parser: Add missing Intel CPU events to parser
  perf script: Allow --symbol to accept hexadecimal addresses
  perf report/top TUI: Fix title line formatting
  perf top: Support hotkey to change sort order
  perf top: Support --group-sort-idx to change the sort order
  perf symbols: Fix arm64 gap between kernel start and module end
  perf build-test: Honour JOBS to override detection of number of cores
  perf script: Add --show-cgroup-events option
  perf top: Add --all-cgroups option
  perf record: Add --all-cgroups option
  perf record: Support synthesizing cgroup events
  perf report: Add 'cgroup' sort key
  perf cgroup: Maintain cgroup hierarchy
  perf tools: Basic support for CGROUP event
  ...

1 files changed, 8 insertions, 6 deletions

diff --git a/tools/perf/Documentation/perf-config.txt b/tools/perf/Documentation/perf-config.txt
index 8ead55593984..f16d8a71d3f5 100644
--- a/tools/perf/Documentation/perf-config.txt
+++ b/tools/perf/Documentation/perf-config.txt
@@ -405,14 +405,16 @@ ui.*::
 		This option is only applied to TUI.
 
 call-graph.*::
-	When sub-commands 'top' and 'report' work with -g/—-children
-	there're options in control of call-graph.
+	The following controls the handling of call-graphs (obtained via the
+	-g/--call-graph options).
 
 	call-graph.record-mode::
-		The record-mode can be 'fp' (frame pointer), 'dwarf' and 'lbr'.
-		The value of 'dwarf' is effective only if perf detect needed library
-		(libunwind or a recent version of libdw).
-		'lbr' only work for cpus that support it.
+		The mode for user space can be 'fp' (frame pointer), 'dwarf'
+		and 'lbr'.  The value 'dwarf' is effective only if libunwind
+		(or a recent version of libdw) is present on the system;
+		the value 'lbr' only works for certain cpus. The method for
+		kernel space is controlled not by this option but by the
+		kernel config (CONFIG_UNWINDER_*).
 
 	call-graph.dump-size::
 		The size of stack to dump in order to do post-unwinding. Default is 8192 (byte).