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authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>2014-04-08 17:26:21 -0400
committerSteven Rostedt <rostedt@goodmis.org>2014-04-08 20:43:28 -0400
commitde7b2973903c6cc50b31ee5682a69b2219b9919d (patch)
treea5b9d78102854b0073f5893cafb29920f8fb55e1 /include
parent68114e5eb862ad0a7a261b91497281b026102715 (diff)
tracepoint: Use struct pointer instead of name hash for reg/unreg tracepoints
Register/unregister tracepoint probes with struct tracepoint pointer rather than tracepoint name. This change, which vastly simplifies tracepoint.c, has been proposed by Steven Rostedt. It also removes 8.8kB (mostly of text) to the vmlinux size. From this point on, the tracers need to pass a struct tracepoint pointer to probe register/unregister. A probe can now only be connected to a tracepoint that exists. Moreover, tracers are responsible for unregistering the probe before the module containing its associated tracepoint is unloaded. text data bss dec hex filename 10443444 4282528 10391552 25117524 17f4354 vmlinux.orig 10434930 4282848 10391552 25109330 17f2352 vmlinux Link: http://lkml.kernel.org/r/1396992381-23785-2-git-send-email-mathieu.desnoyers@efficios.com CC: Ingo Molnar <mingo@kernel.org> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Frank Ch. Eigler <fche@redhat.com> CC: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> [ SDR - fixed return val in void func in tracepoint_module_going() ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/ftrace_event.h22
-rw-r--r--include/linux/tracepoint.h41
-rw-r--r--include/trace/ftrace.h9
3 files changed, 51 insertions, 21 deletions
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index cdc30111d2f8..d16da3e53bc7 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -7,6 +7,7 @@
#include <linux/percpu.h>
#include <linux/hardirq.h>
#include <linux/perf_event.h>
+#include <linux/tracepoint.h>
struct trace_array;
struct trace_buffer;
@@ -232,6 +233,7 @@ enum {
TRACE_EVENT_FL_IGNORE_ENABLE_BIT,
TRACE_EVENT_FL_WAS_ENABLED_BIT,
TRACE_EVENT_FL_USE_CALL_FILTER_BIT,
+ TRACE_EVENT_FL_TRACEPOINT_BIT,
};
/*
@@ -244,6 +246,7 @@ enum {
* (used for module unloading, if a module event is enabled,
* it is best to clear the buffers that used it).
* USE_CALL_FILTER - For ftrace internal events, don't use file filter
+ * TRACEPOINT - Event is a tracepoint
*/
enum {
TRACE_EVENT_FL_FILTERED = (1 << TRACE_EVENT_FL_FILTERED_BIT),
@@ -252,12 +255,17 @@ enum {
TRACE_EVENT_FL_IGNORE_ENABLE = (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT),
TRACE_EVENT_FL_WAS_ENABLED = (1 << TRACE_EVENT_FL_WAS_ENABLED_BIT),
TRACE_EVENT_FL_USE_CALL_FILTER = (1 << TRACE_EVENT_FL_USE_CALL_FILTER_BIT),
+ TRACE_EVENT_FL_TRACEPOINT = (1 << TRACE_EVENT_FL_TRACEPOINT_BIT),
};
struct ftrace_event_call {
struct list_head list;
struct ftrace_event_class *class;
- char *name;
+ union {
+ char *name;
+ /* Set TRACE_EVENT_FL_TRACEPOINT flag when using "tp" */
+ struct tracepoint *tp;
+ };
struct trace_event event;
const char *print_fmt;
struct event_filter *filter;
@@ -271,6 +279,7 @@ struct ftrace_event_call {
* bit 3: ftrace internal event (do not enable)
* bit 4: Event was enabled by module
* bit 5: use call filter rather than file filter
+ * bit 6: Event is a tracepoint
*/
int flags; /* static flags of different events */
@@ -283,6 +292,15 @@ struct ftrace_event_call {
#endif
};
+static inline const char *
+ftrace_event_name(struct ftrace_event_call *call)
+{
+ if (call->flags & TRACE_EVENT_FL_TRACEPOINT)
+ return call->tp ? call->tp->name : NULL;
+ else
+ return call->name;
+}
+
struct trace_array;
struct ftrace_subsystem_dir;
@@ -353,7 +371,7 @@ struct ftrace_event_file {
#define __TRACE_EVENT_FLAGS(name, value) \
static int __init trace_init_flags_##name(void) \
{ \
- event_##name.flags = value; \
+ event_##name.flags |= value; \
return 0; \
} \
early_initcall(trace_init_flags_##name);
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 812b2553dfd8..08150e265761 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -6,7 +6,7 @@
*
* See Documentation/trace/tracepoints.txt.
*
- * (C) Copyright 2008 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ * Copyright (C) 2008-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
* Heavily inspired from the Linux Kernel Markers.
*
@@ -21,6 +21,7 @@
struct module;
struct tracepoint;
+struct notifier_block;
struct tracepoint_func {
void *func;
@@ -35,18 +36,13 @@ struct tracepoint {
struct tracepoint_func __rcu *funcs;
};
-/*
- * Connect a probe to a tracepoint.
- * Internal API, should not be used directly.
- */
-extern int tracepoint_probe_register(const char *name, void *probe, void *data);
-
-/*
- * Disconnect a probe from a tracepoint.
- * Internal API, should not be used directly.
- */
extern int
-tracepoint_probe_unregister(const char *name, void *probe, void *data);
+tracepoint_probe_register(struct tracepoint *tp, void *probe, void *data);
+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),
+ void *priv);
#ifdef CONFIG_MODULES
struct tp_module {
@@ -54,12 +50,25 @@ struct tp_module {
unsigned int num_tracepoints;
struct tracepoint * const *tracepoints_ptrs;
};
+
bool trace_module_has_bad_taint(struct module *mod);
+extern int register_tracepoint_module_notifier(struct notifier_block *nb);
+extern int unregister_tracepoint_module_notifier(struct notifier_block *nb);
#else
static inline bool trace_module_has_bad_taint(struct module *mod)
{
return false;
}
+static inline
+int register_tracepoint_module_notifier(struct notifier_block *nb)
+{
+ return 0;
+}
+static inline
+int unregister_tracepoint_module_notifier(struct notifier_block *nb)
+{
+ return 0;
+}
#endif /* CONFIG_MODULES */
/*
@@ -160,14 +169,14 @@ static inline void tracepoint_synchronize_unregister(void)
static inline int \
register_trace_##name(void (*probe)(data_proto), void *data) \
{ \
- return tracepoint_probe_register(#name, (void *)probe, \
- data); \
+ return tracepoint_probe_register(&__tracepoint_##name, \
+ (void *)probe, data); \
} \
static inline int \
unregister_trace_##name(void (*probe)(data_proto), void *data) \
{ \
- return tracepoint_probe_unregister(#name, (void *)probe, \
- data); \
+ return tracepoint_probe_unregister(&__tracepoint_##name,\
+ (void *)probe, data); \
} \
static inline void \
check_trace_callback_type_##name(void (*cb)(data_proto)) \
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 8765126b328c..9c44c11cd9bb 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -470,10 +470,11 @@ static inline notrace int ftrace_get_offsets_##call( \
* };
*
* static struct ftrace_event_call event_<call> = {
- * .name = "<call>",
+ * .tp = &__tracepoint_<call>,
* .class = event_class_<template>,
* .event = &ftrace_event_type_<call>,
* .print_fmt = print_fmt_<call>,
+ * .flags = TRACE_EVENT_FL_TRACEPOINT,
* };
* // its only safe to use pointers when doing linker tricks to
* // create an array.
@@ -605,10 +606,11 @@ static struct ftrace_event_class __used __refdata event_class_##call = { \
#define DEFINE_EVENT(template, call, proto, args) \
\
static struct ftrace_event_call __used event_##call = { \
- .name = #call, \
+ .tp = &__tracepoint_##call, \
.class = &event_class_##template, \
.event.funcs = &ftrace_event_type_funcs_##template, \
.print_fmt = print_fmt_##template, \
+ .flags = TRACE_EVENT_FL_TRACEPOINT, \
}; \
static struct ftrace_event_call __used \
__attribute__((section("_ftrace_events"))) *__event_##call = &event_##call
@@ -619,10 +621,11 @@ __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call
static const char print_fmt_##call[] = print; \
\
static struct ftrace_event_call __used event_##call = { \
- .name = #call, \
+ .tp = &__tracepoint_##call, \
.class = &event_class_##template, \
.event.funcs = &ftrace_event_type_funcs_##call, \
.print_fmt = print_fmt_##call, \
+ .flags = TRACE_EVENT_FL_TRACEPOINT, \
}; \
static struct ftrace_event_call __used \
__attribute__((section("_ftrace_events"))) *__event_##call = &event_##call