perf report: Add --hierarchy option

The --hierarchy option is to show output in hierarchy mode.  It extends
folding/unfolding in the TUI and GTK browsers to support sort items as
well as callchains.  Users can toggle the items to see the performance
result at wanted level.

  $ perf report --hierarchy --tui
   Overhead       Command / Shared Object / Symbol
  --------------------------------------------------
  +  32.96%       gnome-shell
  -  15.11%       swapper
     -  14.97%       [kernel.vmlinux]
           6.82%        [k] intel_idle
           0.66%        [k] menu_select
           0.43%        [k] __hrtimer_start_range_ns
  ...
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1456326830-30456-17-git-send-email-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-report.txt

@@ -401,6 +401,9 @@ include::itrace.txt[]
 --raw-trace::
 	When displaying traceevent output, do not use print fmt or plugins.
 
+--hierarchy::
+	Enable hierarchical output.
+
 include::callchain-overhead-calculation.txt[]
 
 SEE ALSO

tools/perf/Documentation/tips.txt

@@ -27,3 +27,4 @@ Skip collecing build-id when recording: perf record -B
 To change sampling frequency to 100 Hz: perf record -F 100
 See assembly instructions with percentage: perf annotate <symbol>
 If you prefer Intel style assembly, try: perf annotate -M intel
+For hierarchical output, try: perf report --hierarchy

tools/perf/builtin-report.c

@@ -811,6 +811,8 @@ int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused)
 		    "only show processor socket that match with this filter"),
 	OPT_BOOLEAN(0, "raw-trace", &symbol_conf.raw_trace,
 		    "Show raw trace event output (do not use print fmt or plugins)"),
+	OPT_BOOLEAN(0, "hierarchy", &symbol_conf.report_hierarchy,
+		    "Show entries in a hierarchy"),
 	OPT_END()
 	};
 	struct perf_data_file file = {
@@ -920,6 +922,21 @@ int cmd_report(int argc, const char **argv, const char *prefix __maybe_unused)
 		symbol_conf.cumulate_callchain = false;
 	}
 
+	if (symbol_conf.report_hierarchy) {
+		/* disable incompatible options */
+		symbol_conf.event_group = false;
+		symbol_conf.cumulate_callchain = false;
+
+		if (field_order) {
+			pr_err("Error: --hierarchy and --fields options cannot be used together\n");
+			parse_options_usage(report_usage, options, "F", 1);
+			parse_options_usage(NULL, options, "hierarchy", 0);
+			goto error;
+		}
+
+		sort__need_collapse = true;
+	}
+
 	/* Force tty output for header output and per-thread stat. */
 	if (report.header || report.header_only || report.show_threads)
 		use_browser = 0;