Re: [PATCH 2/8] tracing: create automated trace defines

Jeremy Fitzhardinge
2009-04-14T23:44:22Z

How about something like this:

>From f7fa71c046bc383706bf58503c4b75e05e252152 Mon Sep 17 00:00:00 2001
From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Date: Tue, 14 Apr 2009 16:41:18 -0700
Subject: [PATCH] tracing: move __DO_TRACE out of line

Mainly simplify linux/tracepoint.h's include dependencies (removes
rcupdate.h), but it can't help with icache locality, since it
definitely moves the code out of line, rather than relying on gcc
to do it.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 4353f3f..1052e33 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -15,7 +15,6 @@
*/

#include <linux/types.h>
-#include <linux/rcupdate.h>

struct module;
struct tracepoint;
@@ -42,19 +41,20 @@ struct tracepoint {
* it_func[0] is never NULL because there is at least one element in the array
* when the array itself is non NULL.
*/
-#define __DO_TRACE(tp, proto, args) \
- do { \
+#define DEFINE_DO_TRACE(name, proto, args) \
+ void __do_trace_##name(struct tracepoint *tp, TP_PROTO(proto)) \
+ { \
void **it_func; \
\
rcu_read_lock_sched_notrace(); \
- it_func = rcu_dereference((tp)->funcs); \
+ it_func = rcu_dereference(tp->funcs); \
if (it_func) { \
do { \
((void(*)(proto))(*it_func))(args); \
} while (*(++it_func)); \
} \
rcu_read_unlock_sched_notrace(); \
- } while (0)
+ }

/*
* Make sure the alignment of the structure in the __tracepoints section will
@@ -63,11 +63,13 @@ struct tracepoint {
*/
#define DECLARE_TRACE(name, proto, args) \
extern struct tracepoint __tracepoint_##name; \
+ extern void __do_trace_##name(struct tracepoint *tp, \
+ TP_PROTO(proto)); \
static inline void trace_##name(proto) \
{ \
if (unlikely(__tracepoint_##name.state)) \
- __DO_TRACE(&__tracepoint_##name, \
- TP_PROTO(proto), TP_ARGS(args)); \
+ __do_trace_##name(&__tracepoint_##name, \
+ TP_ARGS(args)); \
} \
static inline int register_trace_##name(void (*probe)(proto)) \
{ \
@@ -151,10 +153,7 @@ extern int tracepoint_get_iter_range(struct tracepoint **tracepoint,
* probe unregistration and the end of module exit to make sure there is no
* caller executing a probe when it is freed.
*/
-static inline void tracepoint_synchronize_unregister(void)
-{
- synchronize_sched();
-}
+extern void tracepoint_synchronize_unregister(void);

#define PARAMS(args...) args

diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h
index 980eb66..1a0502e 100644
--- a/include/trace/define_trace.h
+++ b/include/trace/define_trace.h
@@ -24,14 +24,17 @@

#undef TRACE_EVENT
#define TRACE_EVENT(name, proto, args, tstruct, assign, print) \
+ DEFINE_DO_TRACE(name, TP_PROTO(proto), TP_ARGS(args)) \
DEFINE_TRACE(name)

#undef TRACE_FORMAT
-#define TRACE_FORMAT(name, proto, args, print) \
+#define TRACE_FORMAT(name, proto, args, print) \
+ DEFINE_DO_TRACE(name, TP_PROTO(proto), TP_ARGS(args)) \
DEFINE_TRACE(name)

#undef DECLARE_TRACE
-#define DECLARE_TRACE(name, proto, args) \
+#define DECLARE_TRACE(name, proto, args) \
+ DEFINE_DO_TRACE(name, TP_PROTO(proto), TP_ARGS(args)) \
DEFINE_TRACE(name)

#undef TRACE_INCLUDE
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 1ef5d3a..6ac1f48 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -545,6 +545,12 @@ void tracepoint_iter_reset(struct tracepoint_iter *iter)
}
EXPORT_SYMBOL_GPL(tracepoint_iter_reset);

+void tracepoint_synchronize_unregister(void)
+{
+ synchronize_sched();
+}
+EXPORT_SYMBOL_GPL(tracepoint_synchronize_unregister);
+
#ifdef CONFIG_MODULES

int tracepoint_module_notify(struct notifier_block *self,