perf ftrace: Add option 'verbose' to show more info for graph tracer

Sometimes we want ftrace display more and longer information about the
trace.

  $ sudo perf ftrace -G '*'
   2)   0.979 us    |  mutex_unlock();
   2)   1.540 us    |  __fsnotify_parent();
   2)   0.433 us    |  fsnotify();

  $ sudo perf ftrace -G '*' --graph-opts verbose
  14160.770883 |   0)  <...>-47814   |  .... |   1.289 us    |  mutex_unlock();
  14160.770886 |   0)  <...>-47814   |  .... |   1.624 us    |  __fsnotify_parent();
  14160.770887 |   0)  <...>-47814   |  .... |   0.636 us    |  fsnotify();
  14160.770888 |   0)  <...>-47814   |  .... |   0.328 us    |  __sb_end_write();
  14160.770888 |   0)  <...>-47814   |  d... |   0.430 us    |  fpregs_assert_state_consistent();
  14160.770889 |   0)  <...>-47814   |  d... |               |  do_syscall_64() {
  14160.770889 |   0)  <...>-47814   |  .... |               |    __x64_sys_close() {

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: http://lore.kernel.org/lkml/20200808023141.14227-13-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-ftrace.txt

@@ -106,6 +106,7 @@ OPTIONS
 	List of options allowed to set:
 	  nosleep-time - Measure on-CPU time only for function_graph tracer.
 	  noirqs       - Ignore functions that happen inside interrupt.
+	  verbose      - Show process names, PIDs, timestamps, etc.
 
 SEE ALSO
 --------

tools/perf/builtin-ftrace.c

@@ -47,6 +47,7 @@ struct perf_ftrace {
 	int			func_irq_info;
 	int			graph_nosleep_time;
 	int			graph_noirqs;
+	int			graph_verbose;
 };
 
 struct filter_entry {
@@ -210,6 +211,9 @@ static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
 	write_tracing_option_file("func_stack_trace", "0");
 	write_tracing_option_file("sleep-time", "1");
 	write_tracing_option_file("funcgraph-irqs", "1");
+	write_tracing_option_file("funcgraph-proc", "0");
+	write_tracing_option_file("funcgraph-abstime", "0");
+	write_tracing_option_file("latency-format", "0");
 	write_tracing_option_file("irq-info", "0");
 }
 
@@ -425,6 +429,23 @@ static int set_tracing_funcgraph_irqs(struct perf_ftrace *ftrace)
 	return 0;
 }
 
+static int set_tracing_funcgraph_verbose(struct perf_ftrace *ftrace)
+{
+	if (!ftrace->graph_verbose)
+		return 0;
+
+	if (write_tracing_option_file("funcgraph-proc", "1") < 0)
+		return -1;
+
+	if (write_tracing_option_file("funcgraph-abstime", "1") < 0)
+		return -1;
+
+	if (write_tracing_option_file("latency-format", "1") < 0)
+		return -1;
+
+	return 0;
+}
+
 static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 {
 	char *trace_file;
@@ -519,6 +540,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 		goto out_reset;
 	}
 
+	if (set_tracing_funcgraph_verbose(ftrace) < 0) {
+		pr_err("failed to set tracing option funcgraph-proc/funcgraph-abstime\n");
+		goto out_reset;
+	}
+
 	if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
 		pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
 		goto out_reset;
@@ -700,6 +726,7 @@ static int parse_graph_tracer_opts(const struct option *opt,
 	struct sublevel_option graph_tracer_opts[] = {
 		{ .name = "nosleep-time",	.value_ptr = &ftrace->graph_nosleep_time },
 		{ .name = "noirqs",		.value_ptr = &ftrace->graph_noirqs },
+		{ .name = "verbose",		.value_ptr = &ftrace->graph_verbose },
 		{ .name = NULL, }
 	};
 
@@ -771,7 +798,7 @@ int cmd_ftrace(int argc, const char **argv)
 	OPT_INTEGER('D', "graph-depth", &ftrace.graph_depth,
 		    "Max depth for function graph tracer"),
 	OPT_CALLBACK(0, "graph-opts", &ftrace, "options",
-		     "graph tracer options, available options: nosleep-time,noirqs",
+		     "graph tracer options, available options: nosleep-time,noirqs,verbose",
 		     parse_graph_tracer_opts),
 	OPT_CALLBACK('m', "buffer-size", &ftrace.percpu_buffer_size, "size",
 		     "size of per cpu buffer", parse_buffer_size),