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/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index a6b3705..185c39f 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -858,11 +858,11 @@
When enabled, it will account time the task has been
scheduled out as part of the function call.
- graph-time - When running function graph tracer, to include the
- time to call nested functions. When this is not set,
- the time reported for the function will only include
- the time the function itself executed for, not the time
- for functions that it called.
+ graph-time - When running function profiler with function graph tracer,
+ to include the time to call nested functions. When this is
+ not set, the time reported for the function will only
+ include the time the function itself executed for, not the
+ time for functions that it called.
record-cmd - When any event or tracer is enabled, a hook is enabled
in the sched_switch trace point to fill comm cache
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 7d565af..1e2b316 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -794,7 +794,9 @@
unsigned long ret;
unsigned long func;
unsigned long long calltime;
+#ifdef CONFIG_FUNCTION_PROFILER
unsigned long long subtime;
+#endif
unsigned long fp;
};
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;