tracepoint: Give priority to probes of tracepoints

[cascardo/linux.git] / include / linux / tracepoint.h

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index a5f7f3e..6b79537 100644 (file)
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -26,6 +26,7 @@ struct notifier_block;
 struct tracepoint_func {
        void *func;
        void *data;
+       int prio;
 };
 
 struct tracepoint {
@@ -42,9 +43,14 @@ struct trace_enum_map {
        unsigned long           enum_value;
 };
 
+#define TRACEPOINT_DEFAULT_PRIO        10
+
 extern int
 tracepoint_probe_register(struct tracepoint *tp, void *probe, void *data);
 extern int
+tracepoint_probe_register_prio(struct tracepoint *tp, void *probe, void *data,
+                              int prio);
+extern int
 tracepoint_probe_unregister(struct tracepoint *tp, void *probe, void *data);
 extern void
 for_each_kernel_tracepoint(void (*fct)(struct tracepoint *tp, void *priv),
@@ -111,7 +117,18 @@ extern void syscall_unregfunc(void);
 #define TP_ARGS(args...)       args
 #define TP_CONDITION(args...)  args
 
-#ifdef CONFIG_TRACEPOINTS
+/*
+ * Individual subsystem my have a separate configuration to
+ * enable their tracepoints. By default, this file will create
+ * the tracepoints if CONFIG_TRACEPOINT is defined. If a subsystem
+ * wants to be able to disable its tracepoints from being created
+ * it can define NOTRACE before including the tracepoint headers.
+ */
+#if defined(CONFIG_TRACEPOINTS) && !defined(NOTRACE)
+#define TRACEPOINTS_ENABLED
+#endif
+
+#ifdef TRACEPOINTS_ENABLED
 
 /*
  * it_func[0] is never NULL because there is at least one element in the array
@@ -196,6 +213,13 @@ extern void syscall_unregfunc(void);
                                                (void *)probe, data);   \
        }                                                               \
        static inline int                                               \
+       register_trace_prio_##name(void (*probe)(data_proto), void *data,\
+                                  int prio)                            \
+       {                                                               \
+               return tracepoint_probe_register_prio(&__tracepoint_##name, \
+                                             (void *)probe, data, prio); \
+       }                                                               \
+       static inline int                                               \
        unregister_trace_##name(void (*probe)(data_proto), void *data)  \
        {                                                               \
                return tracepoint_probe_unregister(&__tracepoint_##name,\
@@ -234,7 +258,7 @@ extern void syscall_unregfunc(void);
 #define EXPORT_TRACEPOINT_SYMBOL(name)                                 \
        EXPORT_SYMBOL(__tracepoint_##name)
 
-#else /* !CONFIG_TRACEPOINTS */
+#else /* !TRACEPOINTS_ENABLED */
 #define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \
        static inline void trace_##name(proto)                          \
        { }                                                             \
@@ -266,7 +290,7 @@ extern void syscall_unregfunc(void);
 #define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
 #define EXPORT_TRACEPOINT_SYMBOL(name)
 
-#endif /* CONFIG_TRACEPOINTS */
+#endif /* TRACEPOINTS_ENABLED */
 
 #ifdef CONFIG_TRACING
 /**