trace: add non-hierarchical function_graph option

Add the 'funcgraph-flat' option to the function_graph tracer to use the default
trace printing format rather than the hierarchical formatting normally used.

Change-Id: If2900bfb86e6f8f51379f56da4f6fabafa630909
Signed-off-by: Jamie Gennis <jgennis@google.com>

1 files changed, 13 insertions, 30 deletions

diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index f0a0c982cde..2cd5849153a 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -65,6 +65,9 @@ struct fgraph_data {
 
 #define TRACE_GRAPH_INDENT	2
 
+/* Flag options */
+#define TRACE_GRAPH_PRINT_FLAT		0x80
+
 static unsigned int max_depth;
 
 static struct tracer_opt trace_opts[] = {
@@ -84,6 +87,8 @@ static struct tracer_opt trace_opts[] = {
 	{ TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) },
 	/* Display function name after trailing } */
 	{ TRACER_OPT(funcgraph-tail, TRACE_GRAPH_PRINT_TAIL) },
+	/* Use standard trace formatting rather than hierarchical */
+	{ TRACER_OPT(funcgraph-flat, TRACE_GRAPH_PRINT_FLAT) },
 	{ } /* Empty entry */
 };
 
@@ -1314,6 +1319,9 @@ print_graph_function_flags(struct trace_iterator *iter, u32 flags)
 	int cpu = iter->cpu;
 	int ret;
 
+	if (flags & TRACE_GRAPH_PRINT_FLAT)
+		return TRACE_TYPE_UNHANDLED;
+
 	if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) {
 		per_cpu_ptr(data->cpu_data, cpu)->ignore = 0;
 		return TRACE_TYPE_HANDLED;
@@ -1371,13 +1379,6 @@ print_graph_function(struct trace_iterator *iter)
 	return print_graph_function_flags(iter, tracer_flags.val);
 }
 
-static enum print_line_t
-print_graph_function_event(struct trace_iterator *iter, int flags,
-			   struct trace_event *event)
-{
-	return print_graph_function(iter);
-}
-
 static void print_lat_header(struct seq_file *s, u32 flags)
 {
 	static const char spaces[] = "                "	/* 16 spaces */
@@ -1444,6 +1445,11 @@ void print_graph_headers_flags(struct seq_file *s, u32 flags)
 {
 	struct trace_iterator *iter = s->private;
 
+	if (flags & TRACE_GRAPH_PRINT_FLAT) {
+		trace_default_header(s);
+		return;
+	}
+
 	if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
 		return;
 
@@ -1515,19 +1521,6 @@ func_graph_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
 	return 0;
 }
 
-static struct trace_event_functions graph_functions = {
-	.trace		= print_graph_function_event,
-};
-
-static struct trace_event graph_trace_entry_event = {
-	.type		= TRACE_GRAPH_ENT,
-	.funcs		= &graph_functions,
-};
-
-static struct trace_event graph_trace_ret_event = {
-	.type		= TRACE_GRAPH_RET,
-	.funcs		= &graph_functions
-};
 
 static struct tracer graph_trace __tracer_data = {
 	.name		= "function_graph",
@@ -1604,16 +1597,6 @@ static __init int init_graph_trace(void)
 {
 	max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
 
-	if (!register_ftrace_event(&graph_trace_entry_event)) {
-		pr_warning("Warning: could not register graph trace events\n");
-		return 1;
-	}
-
-	if (!register_ftrace_event(&graph_trace_ret_event)) {
-		pr_warning("Warning: could not register graph trace events\n");
-		return 1;
-	}
-
 	return register_tracer(&graph_trace);
 }