ftrace: Allow for function tracing instance to filter functions

Create a "set_ftrace_filter" and "set_ftrace_notrace" files in the instance directories to let users filter of functions to trace for the given instance.

Steven Rostedt (Red Hat) committed 12 years ago

Commit 591dffd1 parent e3b3e2e5 files · +96 −14Browse files

Showing the changes to kernel/trace/trace_functions.c (1 of 5 files). Show all

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kernel/trace/trace_functions.c+32−8

@@ -52,10 +52,34 @@ static int allocate_ftrace_ops(struct trace_array *tr) · 51 unmodified lines
52	52	return 0;
53	53	}
54	54
	55	+
	56	+int ftrace_create_function_files(struct trace_array *tr,
	57	+ struct dentry *parent)
	58	+{
	59	+ int ret;
	60	+
	61	+ /* The top level array uses the "global_ops". */
	62	+ if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL)) {
	63	+ ret = allocate_ftrace_ops(tr);
	64	+ if (ret)
	65	+ return ret;
	66	+ }
	67	+
	68	+ ftrace_create_filter_files(tr->ops, parent);
	69	+
	70	+ return 0;
	71	+}
	72	+
	73	+void ftrace_destroy_function_files(struct trace_array *tr)
	74	+{
	75	+ ftrace_destroy_filter_files(tr->ops);
	76	+ kfree(tr->ops);
	77	+ tr->ops = NULL;
	78	+}
	79	+
55	80	static int function_trace_init(struct trace_array *tr)
56	81	{
57	82	struct ftrace_ops *ops;
58		− int ret;
59	83
60	84	if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
61	85	/* There's only one global tr */
@@ -69,10 +93,13 @@ static int function_trace_init(struct trace_array *tr) · 7 unmodified lines
69	93	else
70	94	ops = &trace_ops;
71	95	tr->ops = ops;
72		− } else {
73		− ret = allocate_ftrace_ops(tr);
74		− if (ret)
75		− return ret;
	96	+ } else if (!tr->ops) {
	97	+ /*
	98	+ * Instance trace_arrays get their ops allocated
	99	+ * at instance creation. Unless it failed
	100	+ * the allocation.
	101	+ */
	102	+ return -ENOMEM;
76	103	}
77	104
78	105	tr->trace_buffer.cpu = get_cpu();
@@ -87,9 +114,6 @@ static void function_trace_reset(struct trace_array *tr) · 8 unmodified lines
87	114	{
88	115	tracing_stop_function_trace(tr);
89	116	tracing_stop_cmdline_record();
90		− if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL))
91		− kfree(tr->ops);
92		− tr->ops = NULL;
93	117	}
94	118
95	119	static void function_trace_start(struct trace_array *tr)