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-rw-r--r--include/linux/tracepoint.h39
1 files changed, 32 insertions, 7 deletions
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index a5f7f3e..696a339c 100644
--- 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
@@ -167,10 +184,11 @@ extern void syscall_unregfunc(void);
* structure. Force alignment to the same alignment as the section start.
*
* When lockdep is enabled, we make sure to always do the RCU portions of
- * the tracepoint code, regardless of whether tracing is on or we match the
- * condition. This lets us find RCU issues triggered with tracepoints even
- * when this tracepoint is off. This code has no purpose other than poking
- * RCU a bit.
+ * the tracepoint code, regardless of whether tracing is on. However,
+ * don't check if the condition is false, due to interaction with idle
+ * instrumentation. This lets us find RCU issues triggered with tracepoints
+ * even when this tracepoint is off. This code has no purpose other than
+ * poking RCU a bit.
*/
#define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \
extern struct tracepoint __tracepoint_##name; \
@@ -196,6 +214,13 @@ 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 +259,7 @@ 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 +291,7 @@ 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
/**
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