ftrace: Access ret_stack->subtime only in the function profiler
The subtime is used only for function profiler with function graph
tracer enabled. Move the definition of subtime under
CONFIG_FUNCTION_PROFILER to reduce the memory usage. Also move the
initialization of subtime into the graph entry callback.
Link: http://lkml.kernel.org/r/20160831025529.24018-1-namhyung@kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 84752c8..2050a765 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -872,7 +872,13 @@
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static int profile_graph_entry(struct ftrace_graph_ent *trace)
{
+ int index = trace->depth;
+
function_profile_call(trace->func, 0, NULL, NULL);
+
+ if (index >= 0 && index < FTRACE_RETFUNC_DEPTH)
+ current->ret_stack[index].subtime = 0;
+
return 1;
}
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index e14017c..148c90f 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -170,7 +170,6 @@
current->ret_stack[index].ret = ret;
current->ret_stack[index].func = func;
current->ret_stack[index].calltime = calltime;
- current->ret_stack[index].subtime = 0;
current->ret_stack[index].fp = frame_pointer;
*depth = current->curr_ret_stack;