markers: auto enable tracepoints (new API : trace_mark_tp())
Impact: new API
Add a new API trace_mark_tp(), which declares a marker within a
tracepoint probe. When the marker is activated, the tracepoint is
automatically enabled.
No branch test is used at the marker site, because it would be a
duplicate of the branch already present in the tracepoint.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/marker.h b/include/linux/marker.h
index 05ec0df..57a30701 100644
--- a/include/linux/marker.h
+++ b/include/linux/marker.h
@@ -49,6 +49,8 @@
void (*call)(const struct marker *mdata, void *call_private, ...);
struct marker_probe_closure single;
struct marker_probe_closure *multi;
+ const char *tp_name; /* Optional tracepoint name */
+ void *tp_cb; /* Optional tracepoint callback */
} __attribute__((aligned(8)));
#ifdef CONFIG_MARKERS
@@ -73,7 +75,7 @@
__attribute__((section("__markers"), aligned(8))) = \
{ __mstrtab_##name, &__mstrtab_##name[sizeof(#name)], \
0, 0, marker_probe_cb, \
- { __mark_empty_function, NULL}, NULL }; \
+ { __mark_empty_function, NULL}, NULL, NULL, NULL }; \
__mark_check_format(format, ## args); \
if (unlikely(__mark_##name.state)) { \
(*__mark_##name.call) \
@@ -81,11 +83,38 @@
} \
} while (0)
+#define __trace_mark_tp(name, call_private, tp_name, tp_cb, format, args...) \
+ do { \
+ void __check_tp_type(void) \
+ { \
+ register_trace_##tp_name(tp_cb); \
+ } \
+ static const char __mstrtab_##name[] \
+ __attribute__((section("__markers_strings"))) \
+ = #name "\0" format; \
+ static struct marker __mark_##name \
+ __attribute__((section("__markers"), aligned(8))) = \
+ { __mstrtab_##name, &__mstrtab_##name[sizeof(#name)], \
+ 0, 0, marker_probe_cb, \
+ { __mark_empty_function, NULL}, NULL, #tp_name, tp_cb };\
+ __mark_check_format(format, ## args); \
+ (*__mark_##name.call)(&__mark_##name, call_private, \
+ ## args); \
+ } while (0)
+
extern void marker_update_probe_range(struct marker *begin,
struct marker *end);
#else /* !CONFIG_MARKERS */
#define __trace_mark(generic, name, call_private, format, args...) \
__mark_check_format(format, ## args)
+#define __trace_mark_tp(name, call_private, tp_name, tp_cb, format, args...) \
+ do { \
+ void __check_tp_type(void) \
+ { \
+ register_trace_##tp_name(tp_cb); \
+ } \
+ __mark_check_format(format, ## args); \
+ } while (0)
static inline void marker_update_probe_range(struct marker *begin,
struct marker *end)
{ }
@@ -118,6 +147,20 @@
__trace_mark(1, name, NULL, format, ## args)
/**
+ * trace_mark_tp - Marker in a tracepoint callback
+ * @name: marker name, not quoted.
+ * @tp_name: tracepoint name, not quoted.
+ * @tp_cb: tracepoint callback. Should have an associated global symbol so it
+ * is not optimized away by the compiler (should not be static).
+ * @format: format string
+ * @args...: variable argument list
+ *
+ * Places a marker in a tracepoint callback.
+ */
+#define trace_mark_tp(name, tp_name, tp_cb, format, args...) \
+ __trace_mark_tp(name, NULL, tp_name, tp_cb, format, ## args)
+
+/**
* MARK_NOARGS - Format string for a marker with no argument.
*/
#define MARK_NOARGS " "