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authorMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>2008-11-14 17:47:47 -0500
committerIngo Molnar <mingo@elte.hu>2008-11-16 09:01:36 +0100
commit7e066fb870fcd1025ec3ba7bbde5d541094f4ce1 (patch)
tree52acda06de25c029b9834110d7bf6b4abc50353b /include/linux/tracepoint.h
parent32f85742778dfc2c74975cf0b9f5bdb13470cb32 (diff)
downloadlinux-linaro-stable-7e066fb870fcd1025ec3ba7bbde5d541094f4ce1.tar.gz
tracepoints: add DECLARE_TRACE() and DEFINE_TRACE()
Impact: API *CHANGE*. Must update all tracepoint users. Add DEFINE_TRACE() to tracepoints to let them declare the tracepoint structure in a single spot for all the kernel. It helps reducing memory consumption, especially when declaring a lot of tracepoints, e.g. for kmalloc tracing. *API CHANGE WARNING*: now, DECLARE_TRACE() must be used in headers for tracepoint declarations rather than DEFINE_TRACE(). This is the sane way to do it. The name previously used was misleading. Updates scheduler instrumentation to follow this API change. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/tracepoint.h')
-rw-r--r--include/linux/tracepoint.h35
1 files changed, 25 insertions, 10 deletions
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 7e9b42aeae0e..757005458366 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -24,8 +24,12 @@ struct tracepoint {
const char *name; /* Tracepoint name */
int state; /* State. */
void **funcs;
-} __attribute__((aligned(8)));
-
+} __attribute__((aligned(32))); /*
+ * Aligned on 32 bytes because it is
+ * globally visible and gcc happily
+ * align these on the structure size.
+ * Keep in sync with vmlinux.lds.h.
+ */
#define TPPROTO(args...) args
#define TPARGS(args...) args
@@ -55,15 +59,10 @@ struct tracepoint {
* not add unwanted padding between the beginning of the section and the
* structure. Force alignment to the same alignment as the section start.
*/
-#define DEFINE_TRACE(name, proto, args) \
+#define DECLARE_TRACE(name, proto, args) \
+ extern struct tracepoint __tracepoint_##name; \
static inline void trace_##name(proto) \
{ \
- static const char __tpstrtab_##name[] \
- __attribute__((section("__tracepoints_strings"))) \
- = #name; \
- static struct tracepoint __tracepoint_##name \
- __attribute__((section("__tracepoints"), aligned(8))) = \
- { __tpstrtab_##name, 0, NULL }; \
if (unlikely(__tracepoint_##name.state)) \
__DO_TRACE(&__tracepoint_##name, \
TPPROTO(proto), TPARGS(args)); \
@@ -77,11 +76,23 @@ struct tracepoint {
return tracepoint_probe_unregister(#name, (void *)probe);\
}
+#define DEFINE_TRACE(name) \
+ static const char __tpstrtab_##name[] \
+ __attribute__((section("__tracepoints_strings"))) = #name; \
+ struct tracepoint __tracepoint_##name \
+ __attribute__((section("__tracepoints"), aligned(32))) = \
+ { __tpstrtab_##name, 0, NULL }
+
+#define EXPORT_TRACEPOINT_SYMBOL_GPL(name) \
+ EXPORT_SYMBOL_GPL(__tracepoint_##name)
+#define EXPORT_TRACEPOINT_SYMBOL(name) \
+ EXPORT_SYMBOL(__tracepoint_##name)
+
extern void tracepoint_update_probe_range(struct tracepoint *begin,
struct tracepoint *end);
#else /* !CONFIG_TRACEPOINTS */
-#define DEFINE_TRACE(name, proto, args) \
+#define DECLARE_TRACE(name, proto, args) \
static inline void _do_trace_##name(struct tracepoint *tp, proto) \
{ } \
static inline void trace_##name(proto) \
@@ -95,6 +106,10 @@ extern void tracepoint_update_probe_range(struct tracepoint *begin,
return -ENOSYS; \
}
+#define DEFINE_TRACE(name)
+#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
+#define EXPORT_TRACEPOINT_SYMBOL(name)
+
static inline void tracepoint_update_probe_range(struct tracepoint *begin,
struct tracepoint *end)
{ }