tracing/function-return-tracer: change the name into function-graph-tracer

Impact: cleanup

This patch changes the name of the "return function tracer" into
function-graph-tracer which is a more suitable name for a tracing
which makes one able to retrieve the ordered call stack during
the code flow.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 620fead..eb9b901 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -12,7 +12,7 @@
 config HAVE_FUNCTION_TRACER
 	bool
 
-config HAVE_FUNCTION_RET_TRACER
+config HAVE_FUNCTION_GRAPH_TRACER
 	bool
 
 config HAVE_FUNCTION_TRACE_MCOUNT_TEST
@@ -63,15 +63,18 @@
 	  (the bootup default), then the overhead of the instructions is very
 	  small and not measurable even in micro-benchmarks.
 
-config FUNCTION_RET_TRACER
-	bool "Kernel Function return Tracer"
-	depends on HAVE_FUNCTION_RET_TRACER
+config FUNCTION_GRAPH_TRACER
+	bool "Kernel Function Graph Tracer"
+	depends on HAVE_FUNCTION_GRAPH_TRACER
 	depends on FUNCTION_TRACER
 	help
-	  Enable the kernel to trace a function at its return.
-	  It's first purpose is to trace the duration of functions.
-	  This is done by setting the current return address on the thread
-	  info structure of the current task.
+	  Enable the kernel to trace a function at both its return
+	  and its entry.
+	  It's first purpose is to trace the duration of functions and
+	  draw a call graph for each thread with some informations like
+	  the return value.
+	  This is done by setting the current return address on the current
+	  task structure into a stack of calls.
 
 config IRQSOFF_TRACER
 	bool "Interrupts-off Latency Tracer"