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authorLinus Torvalds <torvalds@linux-foundation.org>2024-11-28 11:46:13 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2024-11-28 11:46:13 -0800
commit7af08b57bcb9ebf78675c50069c54125c0a8b795 (patch)
tree29d7a2ca5cc7f9f1b874b1377479cd04caeccb4b /include
parent65ae975e97d5aab3ee9dc5ec701b12090572ed43 (diff)
parent2bd9b57d04df417f31ef54448477c212fcdd14fc (diff)
Merge tag 'trace-v6.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull more tracing updates from Steven Rostedt: - Add trace flag for NEED_RESCHED_LAZY Now that NEED_RESCHED_LAZY is upstream, add it to the status bits of the common_flags. This will now show when the NEED_RESCHED_LAZY flag is set that is used for debugging latency issues in the kernel via a trace. - Remove leftover "__idx" variable when SRCU was removed from the tracepoint code - Add rcu_tasks_trace guard To add a guard() around the tracepoint code, a rcu_tasks_trace guard needs to be created first. - Remove __DO_TRACE() macro and just call __DO_TRACE_CALL() directly The DO_TRACE() macro has conditional locking depending on what was passed into the macro parameters. As the guts of the macro has been moved to __DO_TRACE_CALL() to handle static call logic, there's no reason to keep the __DO_TRACE() macro around. It is better to just do the locking in place without the conditionals and call __DO_TRACE_CALL() from those locations. The "cond" passed in can also be moved out of that macro. This simplifies the code. - Remove the "cond" from the system call tracepoint macros The "cond" variable was added to allow some tracepoints to check a condition within the static_branch (jump/nop) logic. The system calls do not need this. Removing it simplifies the code. - Replace scoped_guard() with just guard() in the tracepoint logic guard() works just as well as scoped_guard() in the tracepoint logic and the scoped_guard() causes some issues. * tag 'trace-v6.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Use guard() rather than scoped_guard() tracing: Remove cond argument from __DECLARE_TRACE_SYSCALL tracing: Remove conditional locking from __DO_TRACE() rcupdate_trace: Define rcu_tasks_trace lock guard tracing: Remove __idx variable from __DO_TRACE tracing: Move it_func[0] comment to the relevant context tracing: Record task flag NEED_RESCHED_LAZY.
Diffstat (limited to 'include')
-rw-r--r--include/linux/rcupdate_trace.h5
-rw-r--r--include/linux/trace_events.h1
-rw-r--r--include/linux/tracepoint.h82
3 files changed, 36 insertions, 52 deletions
diff --git a/include/linux/rcupdate_trace.h b/include/linux/rcupdate_trace.h
index eda493200663..e6c44eb428ab 100644
--- a/include/linux/rcupdate_trace.h
+++ b/include/linux/rcupdate_trace.h
@@ -10,6 +10,7 @@
#include <linux/sched.h>
#include <linux/rcupdate.h>
+#include <linux/cleanup.h>
extern struct lockdep_map rcu_trace_lock_map;
@@ -98,4 +99,8 @@ static inline void rcu_read_lock_trace(void) { BUG(); }
static inline void rcu_read_unlock_trace(void) { BUG(); }
#endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
+DEFINE_LOCK_GUARD_0(rcu_tasks_trace,
+ rcu_read_lock_trace(),
+ rcu_read_unlock_trace())
+
#endif /* __LINUX_RCUPDATE_TRACE_H */
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 016b29a56c87..2a5df5b62cfc 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -184,6 +184,7 @@ unsigned int tracing_gen_ctx_irq_test(unsigned int irqs_status);
enum trace_flag_type {
TRACE_FLAG_IRQS_OFF = 0x01,
+ TRACE_FLAG_NEED_RESCHED_LAZY = 0x02,
TRACE_FLAG_NEED_RESCHED = 0x04,
TRACE_FLAG_HARDIRQ = 0x08,
TRACE_FLAG_SOFTIRQ = 0x10,
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 6073a8c7e38c..76d9055b2cff 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -210,36 +210,6 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
#endif /* CONFIG_HAVE_STATIC_CALL */
/*
- * it_func[0] is never NULL because there is at least one element in the array
- * when the array itself is non NULL.
- *
- * With @syscall=0, the tracepoint callback array dereference is
- * protected by disabling preemption.
- * With @syscall=1, the tracepoint callback array dereference is
- * protected by Tasks Trace RCU, which allows probes to handle page
- * faults.
- */
-#define __DO_TRACE(name, args, cond, syscall) \
- do { \
- int __maybe_unused __idx = 0; \
- \
- if (!(cond)) \
- return; \
- \
- if (syscall) \
- rcu_read_lock_trace(); \
- else \
- preempt_disable_notrace(); \
- \
- __DO_TRACE_CALL(name, TP_ARGS(args)); \
- \
- if (syscall) \
- rcu_read_unlock_trace(); \
- else \
- preempt_enable_notrace(); \
- } while (0)
-
-/*
* Declare an exported function that Rust code can call to trigger this
* tracepoint. This function does not include the static branch; that is done
* in Rust to avoid a function call when the tracepoint is disabled.
@@ -262,7 +232,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
* site if it is not watching, as it will need to be active when the
* tracepoint is enabled.
*/
-#define __DECLARE_TRACE_COMMON(name, proto, args, cond, data_proto) \
+#define __DECLARE_TRACE_COMMON(name, proto, args, data_proto) \
extern int __traceiter_##name(data_proto); \
DECLARE_STATIC_CALL(tp_func_##name, __traceiter_##name); \
extern struct tracepoint __tracepoint_##name; \
@@ -297,41 +267,43 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
}
#define __DECLARE_TRACE(name, proto, args, cond, data_proto) \
- __DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), cond, PARAMS(data_proto)) \
+ __DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), PARAMS(data_proto)) \
static inline void __rust_do_trace_##name(proto) \
{ \
- __DO_TRACE(name, \
- TP_ARGS(args), \
- TP_CONDITION(cond), 0); \
+ if (cond) { \
+ guard(preempt_notrace)(); \
+ __DO_TRACE_CALL(name, TP_ARGS(args)); \
+ } \
} \
static inline void trace_##name(proto) \
{ \
- if (static_branch_unlikely(&__tracepoint_##name.key)) \
- __DO_TRACE(name, \
- TP_ARGS(args), \
- TP_CONDITION(cond), 0); \
+ if (static_branch_unlikely(&__tracepoint_##name.key)) { \
+ if (cond) { \
+ guard(preempt_notrace)(); \
+ __DO_TRACE_CALL(name, TP_ARGS(args)); \
+ } \
+ } \
if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) { \
WARN_ONCE(!rcu_is_watching(), \
"RCU not watching for tracepoint"); \
} \
}
-#define __DECLARE_TRACE_SYSCALL(name, proto, args, cond, data_proto) \
- __DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), cond, PARAMS(data_proto)) \
+#define __DECLARE_TRACE_SYSCALL(name, proto, args, data_proto) \
+ __DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), PARAMS(data_proto)) \
static inline void __rust_do_trace_##name(proto) \
{ \
- __DO_TRACE(name, \
- TP_ARGS(args), \
- TP_CONDITION(cond), 1); \
+ guard(rcu_tasks_trace)(); \
+ __DO_TRACE_CALL(name, TP_ARGS(args)); \
} \
static inline void trace_##name(proto) \
{ \
might_fault(); \
- if (static_branch_unlikely(&__tracepoint_##name.key)) \
- __DO_TRACE(name, \
- TP_ARGS(args), \
- TP_CONDITION(cond), 1); \
- if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) { \
+ if (static_branch_unlikely(&__tracepoint_##name.key)) { \
+ guard(rcu_tasks_trace)(); \
+ __DO_TRACE_CALL(name, TP_ARGS(args)); \
+ } \
+ if (IS_ENABLED(CONFIG_LOCKDEP)) { \
WARN_ONCE(!rcu_is_watching(), \
"RCU not watching for tracepoint"); \
} \
@@ -341,6 +313,9 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
* We have no guarantee that gcc and the linker won't up-align the tracepoint
* structures, so we create an array of pointers that will be used for iteration
* on the tracepoints.
+ *
+ * it_func[0] is never NULL because there is at least one element in the array
+ * when the array itself is non NULL.
*/
#define __DEFINE_TRACE_EXT(_name, _ext, proto, args) \
static const char __tpstrtab_##_name[] \
@@ -412,7 +387,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
#else /* !TRACEPOINTS_ENABLED */
-#define __DECLARE_TRACE(name, proto, args, cond, data_proto) \
+#define __DECLARE_TRACE_COMMON(name, proto, args, data_proto) \
static inline void trace_##name(proto) \
{ } \
static inline int \
@@ -436,7 +411,11 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
return false; \
}
-#define __DECLARE_TRACE_SYSCALL __DECLARE_TRACE
+#define __DECLARE_TRACE(name, proto, args, cond, data_proto) \
+ __DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), PARAMS(data_proto))
+
+#define __DECLARE_TRACE_SYSCALL(name, proto, args, data_proto) \
+ __DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), PARAMS(data_proto))
#define DEFINE_TRACE_FN(name, reg, unreg, proto, args)
#define DEFINE_TRACE_SYSCALL(name, reg, unreg, proto, args)
@@ -502,7 +481,6 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
#define DECLARE_TRACE_SYSCALL(name, proto, args) \
__DECLARE_TRACE_SYSCALL(name, PARAMS(proto), PARAMS(args), \
- cpu_online(raw_smp_processor_id()), \
PARAMS(void *__data, proto))
#define TRACE_EVENT_FLAGS(event, flag)