[PATCH 03/12] add DECLARE_TRACE_WITH_CALLBACK() macro

Jason Baron
2009-08-10T20:54:52Z

Introduce a new 'DECLARE_TRACE_WITH_CALLBACK()' macro, so that tracepoints can
associate an external register/unregister function.

Signed-off-by: Jason Baron <jbaron@redhat.com>

---
include/linux/tracepoint.h | 31 +++++++++++++++++++++++++++----
1 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index b9dc4ca..5984ed0 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -60,8 +60,10 @@ struct tracepoint {
* Make sure the alignment of the structure in the __tracepoints section will
* not add unwanted padding between the beginning of the section and the
* structure. Force alignment to the same alignment as the section start.
+ * An optional set of (un)registration functions can be passed to perform any
+ * additional (un)registration work.
*/
-#define DECLARE_TRACE(name, proto, args) \
+#define DECLARE_TRACE_WITH_CALLBACK(name, proto, args, reg, unreg) \
extern struct tracepoint __tracepoint_##name; \
static inline void trace_##name(proto) \
{ \
@@ -71,13 +73,30 @@ struct tracepoint {
} \
static inline int register_trace_##name(void (*probe)(proto)) \
{ \
- return tracepoint_probe_register(#name, (void *)probe); \
+ int ret; \
+ void (*func)(void) = reg; \
+ \
+ ret = tracepoint_probe_register(#name, (void *)probe); \
+ if (func && !ret) \
+ func(); \
+ return ret; \
} \
static inline int unregister_trace_##name(void (*probe)(proto)) \
{ \
- return tracepoint_probe_unregister(#name, (void *)probe);\
+ int ret; \
+ void (*func)(void) = unreg; \
+ \
+ ret = tracepoint_probe_unregister(#name, (void *)probe);\
+ if (func && !ret) \
+ func(); \
+ return ret; \
}

+
+#define DECLARE_TRACE(name, proto, args) \
+ DECLARE_TRACE_WITH_CALLBACK(name, TP_PROTO(proto), TP_ARGS(args),\
+ NULL, NULL);
+
#define DEFINE_TRACE(name) \
static const char __tpstrtab_##name[] \
__attribute__((section("__tracepoints_strings"))) = #name; \
@@ -94,7 +113,7 @@ extern void tracepoint_update_probe_range(struct tracepoint *begin,
struct tracepoint *end);

#else /* !CONFIG_TRACEPOINTS */
-#define DECLARE_TRACE(name, proto, args) \
+#define DECLARE_TRACE_WITH_CALLBACK(name, proto, args, reg, unreg) \
static inline void _do_trace_##name(struct tracepoint *tp, proto) \
{ } \
static inline void trace_##name(proto) \
@@ -108,6 +127,10 @@ extern void tracepoint_update_probe_range(struct tracepoint *begin,
return -ENOSYS; \
}

+#define DECLARE_TRACE(name, proto, args) \
+ DECLARE_TRACE_WITH_CALLBACK(name, TP_PROTO(proto), TP_ARGS(args),\
+ NULL, NULL);
+
#define DEFINE_TRACE(name)
#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
#define EXPORT_TRACEPOINT_SYMBOL(name)
--
1.6.2.5