tracing: Separate out trace events from global variables

The trace events for ftrace are all defined via global variables.
The arrays of events and event systems are linked to a global list.
This prevents multiple users of the event system (what to enable and
what not to).

By adding descriptors to represent the event/file relation, as well
as to which trace_array descriptor they are associated with, allows
for more than one set of events to be defined. Once the trace events
files have a link between the trace event and the trace_array they
are associated with, we can create multiple trace_arrays that can
record separate events in separate buffers.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 40 insertions, 11 deletions

diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 13a54d0..c7191d4 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -182,18 +182,20 @@ extern int ftrace_event_reg(struct ftrace_event_call *event,
 			    enum trace_reg type, void *data);
 
 enum {
-	TRACE_EVENT_FL_ENABLED_BIT,
 	TRACE_EVENT_FL_FILTERED_BIT,
-	TRACE_EVENT_FL_RECORDED_CMD_BIT,
 	TRACE_EVENT_FL_CAP_ANY_BIT,
 	TRACE_EVENT_FL_NO_SET_FILTER_BIT,
 	TRACE_EVENT_FL_IGNORE_ENABLE_BIT,
 };
 
+/*
+ * Event flags:
+ *  FILTERED	  - The event has a filter attached
+ *  CAP_ANY	  - Any user can enable for perf
+ *  NO_SET_FILTER - Set when filter has error and is to be ignored
+ */
 enum {
-	TRACE_EVENT_FL_ENABLED		= (1 << TRACE_EVENT_FL_ENABLED_BIT),
 	TRACE_EVENT_FL_FILTERED		= (1 << TRACE_EVENT_FL_FILTERED_BIT),
-	TRACE_EVENT_FL_RECORDED_CMD	= (1 << TRACE_EVENT_FL_RECORDED_CMD_BIT),
 	TRACE_EVENT_FL_CAP_ANY		= (1 << TRACE_EVENT_FL_CAP_ANY_BIT),
 	TRACE_EVENT_FL_NO_SET_FILTER	= (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT),
 	TRACE_EVENT_FL_IGNORE_ENABLE	= (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
@@ -203,12 +205,44 @@ struct ftrace_event_call {
 	struct list_head	list;
 	struct ftrace_event_class *class;
 	char			*name;
-	struct dentry		*dir;
 	struct trace_event	event;
 	const char		*print_fmt;
 	struct event_filter	*filter;
+	struct list_head	*files;
 	void			*mod;
 	void			*data;
+	int			flags; /* static flags of different events */
+
+#ifdef CONFIG_PERF_EVENTS
+	int				perf_refcount;
+	struct hlist_head __percpu	*perf_events;
+#endif
+};
+
+struct trace_array;
+struct ftrace_subsystem_dir;
+
+enum {
+	FTRACE_EVENT_FL_ENABLED_BIT,
+	FTRACE_EVENT_FL_RECORDED_CMD_BIT,
+};
+
+/*
+ * Ftrace event file flags:
+ *  ENABELD	  - The event is enabled
+ *  RECORDED_CMD  - The comms should be recorded at sched_switch
+ */
+enum {
+	FTRACE_EVENT_FL_ENABLED		= (1 << FTRACE_EVENT_FL_ENABLED_BIT),
+	FTRACE_EVENT_FL_RECORDED_CMD	= (1 << FTRACE_EVENT_FL_RECORDED_CMD_BIT),
+};
+
+struct ftrace_event_file {
+	struct list_head		list;
+	struct ftrace_event_call	*event_call;
+	struct dentry			*dir;
+	struct trace_array		*tr;
+	struct ftrace_subsystem_dir	*system;
 
 	/*
 	 * 32 bit flags:
@@ -223,17 +257,12 @@ struct ftrace_event_call {
 	 *
 	 * Note: Reads of flags do not hold the event_mutex since
 	 * they occur in critical sections. But the way flags
-	 * is currently used, these changes do no affect the code
+	 * is currently used, these changes do not affect the code
 	 * except that when a change is made, it may have a slight
 	 * delay in propagating the changes to other CPUs due to
 	 * caching and such.
 	 */
 	unsigned int		flags;
-
-#ifdef CONFIG_PERF_EVENTS
-	int				perf_refcount;
-	struct hlist_head __percpu	*perf_events;
-#endif
 };
 
 #define __TRACE_EVENT_FLAGS(name, value)				\