[for-next][PATCH 4/6] tracepoints: Use new static branch API

From: Steven Rostedt
Date: Wed Oct 09 2024 - 09:21:31 EST


From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>

The old static key API is deprecated. Switch to the new one.

Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Alice Ryhl <aliceryhl@xxxxxxxxxx>
Link: https://lore.kernel.org/7a08dae3c5eddb14b13864923c1b58ac1f4af83c.1728414936.git.jpoimboe@xxxxxxxxxx
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
include/linux/tracepoint-defs.h | 4 ++--
include/linux/tracepoint.h | 8 ++++----
kernel/trace/trace_events_hist.c | 2 +-
kernel/trace/trace_events_user.c | 4 ++--
kernel/tracepoint.c | 4 ++--
5 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/include/linux/tracepoint-defs.h b/include/linux/tracepoint-defs.h
index 4dc4955f0fbf..60a6e8314d4c 100644
--- a/include/linux/tracepoint-defs.h
+++ b/include/linux/tracepoint-defs.h
@@ -31,7 +31,7 @@ struct tracepoint_func {

struct tracepoint {
const char *name; /* Tracepoint name */
- struct static_key key;
+ struct static_key_false key;
struct static_call_key *static_call_key;
void *static_call_tramp;
void *iterator;
@@ -83,7 +83,7 @@ struct bpf_raw_event_map {

#ifdef CONFIG_TRACEPOINTS
# define tracepoint_enabled(tp) \
- static_key_false(&(__tracepoint_##tp).key)
+ static_branch_unlikely(&(__tracepoint_##tp).key)
#else
# define tracepoint_enabled(tracepoint) false
#endif
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 93a9f3070b48..2a29334bbc02 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -248,7 +248,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
#define __DECLARE_TRACE_RCU(name, proto, args, cond) \
static inline void trace_##name##_rcuidle(proto) \
{ \
- if (static_key_false(&__tracepoint_##name.key)) \
+ if (static_branch_unlikely(&__tracepoint_##name.key)) \
__DO_TRACE(name, \
TP_ARGS(args), \
TP_CONDITION(cond), 1); \
@@ -274,7 +274,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
extern struct tracepoint __tracepoint_##name; \
static inline void trace_##name(proto) \
{ \
- if (static_key_false(&__tracepoint_##name.key)) \
+ if (static_branch_unlikely(&__tracepoint_##name.key)) \
__DO_TRACE(name, \
TP_ARGS(args), \
TP_CONDITION(cond), 0); \
@@ -311,7 +311,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
static inline bool \
trace_##name##_enabled(void) \
{ \
- return static_key_false(&__tracepoint_##name.key); \
+ return static_branch_unlikely(&__tracepoint_##name.key);\
}

/*
@@ -328,7 +328,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
struct tracepoint __tracepoint_##_name __used \
__section("__tracepoints") = { \
.name = __tpstrtab_##_name, \
- .key = STATIC_KEY_INIT_FALSE, \
+ .key = STATIC_KEY_FALSE_INIT, \
.static_call_key = &STATIC_CALL_KEY(tp_func_##_name), \
.static_call_tramp = STATIC_CALL_TRAMP_ADDR(tp_func_##_name), \
.iterator = &__traceiter_##_name, \
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 5f9119eb7c67..cc2924ad32a3 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -822,7 +822,7 @@ static inline void trace_synth(struct synth_event *event, u64 *var_ref_vals,
{
struct tracepoint *tp = event->tp;

- if (unlikely(atomic_read(&tp->key.enabled) > 0)) {
+ if (unlikely(static_key_enabled(&tp->key))) {
struct tracepoint_func *probe_func_ptr;
synth_probe_func_t probe_func;
void *__data;
diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index 42b0d998d103..17bcad8f79de 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -1676,7 +1676,7 @@ static void update_enable_bit_for(struct user_event *user)
struct tracepoint *tp = &user->tracepoint;
char status = 0;

- if (atomic_read(&tp->key.enabled) > 0) {
+ if (static_key_enabled(&tp->key)) {
struct tracepoint_func *probe_func_ptr;
user_event_func_t probe_func;

@@ -2280,7 +2280,7 @@ static ssize_t user_events_write_core(struct file *file, struct iov_iter *i)
* It's possible key.enabled disables after this check, however
* we don't mind if a few events are included in this condition.
*/
- if (likely(atomic_read(&tp->key.enabled) > 0)) {
+ if (likely(static_key_enabled(&tp->key))) {
struct tracepoint_func *probe_func_ptr;
user_event_func_t probe_func;
struct iov_iter copy;
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 8879da16ef4d..1e3de77ea6b3 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -358,7 +358,7 @@ static int tracepoint_add_func(struct tracepoint *tp,
tracepoint_update_call(tp, tp_funcs);
/* Both iterator and static call handle NULL tp->funcs */
rcu_assign_pointer(tp->funcs, tp_funcs);
- static_key_enable(&tp->key);
+ static_branch_enable(&tp->key);
break;
case TP_FUNC_2: /* 1->2 */
/* Set iterator static call */
@@ -414,7 +414,7 @@ static int tracepoint_remove_func(struct tracepoint *tp,
if (tp->unregfunc && static_key_enabled(&tp->key))
tp->unregfunc();

- static_key_disable(&tp->key);
+ static_branch_disable(&tp->key);
/* Set iterator static call */
tracepoint_update_call(tp, tp_funcs);
/* Both iterator and static call handle NULL tp->funcs */
--
2.45.2