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>
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 2081971..037f7eb 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -158,13 +158,39 @@
*/
struct trace_array {
struct ring_buffer *buffer;
+ struct list_head list;
int cpu;
int buffer_disabled;
+ unsigned int flags;
cycle_t time_start;
+ struct dentry *dir;
+ struct dentry *event_dir;
+ struct list_head systems;
+ struct list_head events;
struct task_struct *waiter;
struct trace_array_cpu *data[NR_CPUS];
};
+enum {
+ TRACE_ARRAY_FL_GLOBAL = (1 << 0)
+};
+
+extern struct list_head ftrace_trace_arrays;
+
+/*
+ * The global tracer (top) should be the first trace array added,
+ * but we check the flag anyway.
+ */
+static inline struct trace_array *top_trace_array(void)
+{
+ struct trace_array *tr;
+
+ tr = list_entry(ftrace_trace_arrays.prev,
+ typeof(*tr), list);
+ WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
+ return tr;
+}
+
#define FTRACE_CMP_TYPE(var, type) \
__builtin_types_compatible_p(typeof(var), type *)
@@ -851,12 +877,19 @@
struct event_subsystem {
struct list_head list;
const char *name;
- struct dentry *entry;
struct event_filter *filter;
- int nr_events;
int ref_count;
};
+struct ftrace_subsystem_dir {
+ struct list_head list;
+ struct event_subsystem *subsystem;
+ struct trace_array *tr;
+ struct dentry *entry;
+ int ref_count;
+ int nr_events;
+};
+
#define FILTER_PRED_INVALID ((unsigned short)-1)
#define FILTER_PRED_IS_RIGHT (1 << 15)
#define FILTER_PRED_FOLD (1 << 15)
@@ -914,7 +947,7 @@
struct trace_seq *s);
extern int apply_event_filter(struct ftrace_event_call *call,
char *filter_string);
-extern int apply_subsystem_event_filter(struct event_subsystem *system,
+extern int apply_subsystem_event_filter(struct ftrace_subsystem_dir *dir,
char *filter_string);
extern void print_subsystem_event_filter(struct event_subsystem *system,
struct trace_seq *s);