Commit 48bcda68 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt (Google)
Browse files

tracing: Remove definition of trace_*_rcuidle() 

The trace_*_rcuidle() variant of a tracepoint was to handle places where a
tracepoint was located but RCU was not "watching". All those locations
have been removed, and RCU should be watching where all tracepoints are
located. We can now remove the trace_*_rcuidle() variant.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Link: https://lore.kernel.org/20241003181629.36209057@gandalf.local.home


Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 4a8840af

include/linux/tracepoint.h

+2 −48
Original line number Diff line number Diff line
@@ -196,67 +196,25 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) 
#define __DO_TRACE_CALL(name, args)	__traceiter_##name(NULL, args)

#endif /* CONFIG_HAVE_STATIC_CALL */



/*

 * ARCH_WANTS_NO_INSTR archs are expected to have sanitized entry and idle

 * code that disallow any/all tracing/instrumentation when RCU isn't watching.

 */

#ifdef CONFIG_ARCH_WANTS_NO_INSTR

#define RCUIDLE_COND(rcuidle)	(rcuidle)

#else

/* srcu can't be used from NMI */

#define RCUIDLE_COND(rcuidle)	(rcuidle && in_nmi())

#endif



/*

 * it_func[0] is never NULL because there is at least one element in the array

 * when the array itself is non NULL.

 */

#define __DO_TRACE(name, args, cond, rcuidle)				\

#define __DO_TRACE(name, args, cond)					\

	do {								\

		int __maybe_unused __idx = 0;				\

									\

		if (!(cond))						\

			return;						\

									\

		if (WARN_ONCE(RCUIDLE_COND(rcuidle),			\

			      "Bad RCU usage for tracepoint"))		\

			return;						\

									\

		/* keep srcu and sched-rcu usage consistent */		\

		preempt_disable_notrace();				\

									\

		/*							\

		 * For rcuidle callers, use srcu since sched-rcu	\

		 * doesn't work from the idle path.			\

		 */							\

		if (rcuidle) {						\

			__idx = srcu_read_lock_notrace(&tracepoint_srcu);\

			ct_irq_enter_irqson();				\

		}							\

									\

		__DO_TRACE_CALL(name, TP_ARGS(args));			\

									\

		if (rcuidle) {						\

			ct_irq_exit_irqson();				\

			srcu_read_unlock_notrace(&tracepoint_srcu, __idx);\

		}							\

									\

		preempt_enable_notrace();				\

	} while (0)



#ifndef MODULE

#define __DECLARE_TRACE_RCU(name, proto, args, cond)			\

	static inline void trace_##name##_rcuidle(proto)		\

	{								\

		if (static_branch_unlikely(&__tracepoint_##name.key))	\

			__DO_TRACE(name,				\

				TP_ARGS(args),				\

				TP_CONDITION(cond), 1);			\

	}

#else

#define __DECLARE_TRACE_RCU(name, proto, args, cond)

#endif



/*

 * Make sure the alignment of the structure in the __tracepoints section will

 * not add unwanted padding between the beginning of the section and the
@@ -277,14 +235,12 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) 
		if (static_branch_unlikely(&__tracepoint_##name.key))	\

			__DO_TRACE(name,				\

				TP_ARGS(args),				\

				TP_CONDITION(cond), 0);			\

				TP_CONDITION(cond));			\

		if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) {		\

			WARN_ONCE(!rcu_is_watching(),			\

				  "RCU not watching for tracepoint");	\

		}							\

	}								\

	__DECLARE_TRACE_RCU(name, PARAMS(proto), PARAMS(args),		\

			    PARAMS(cond))				\

	static inline int						\

	register_trace_##name(void (*probe)(data_proto), void *data)	\

	{								\
@@ -375,8 +331,6 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) 
#define __DECLARE_TRACE(name, proto, args, cond, data_proto)		\

	static inline void trace_##name(proto)				\

	{ }								\

	static inline void trace_##name##_rcuidle(proto)		\

	{ }								\

	static inline int						\

	register_trace_##name(void (*probe)(data_proto),		\

			      void *data)				\

include/trace/events/preemptirq.h

+0 −8
Original line number Diff line number Diff line
@@ -43,8 +43,6 @@ DEFINE_EVENT(preemptirq_template, irq_enable, 
#else

#define trace_irq_enable(...)

#define trace_irq_disable(...)

#define trace_irq_enable_rcuidle(...)

#define trace_irq_disable_rcuidle(...)

#endif



#ifdef CONFIG_TRACE_PREEMPT_TOGGLE
@@ -58,8 +56,6 @@ DEFINE_EVENT(preemptirq_template, preempt_enable, 
#else

#define trace_preempt_enable(...)

#define trace_preempt_disable(...)

#define trace_preempt_enable_rcuidle(...)

#define trace_preempt_disable_rcuidle(...)

#endif



#endif /* _TRACE_PREEMPTIRQ_H */
@@ -69,10 +65,6 @@ DEFINE_EVENT(preemptirq_template, preempt_enable, 
#else /* !CONFIG_PREEMPTIRQ_TRACEPOINTS */

#define trace_irq_enable(...)

#define trace_irq_disable(...)

#define trace_irq_enable_rcuidle(...)

#define trace_irq_disable_rcuidle(...)

#define trace_preempt_enable(...)

#define trace_preempt_disable(...)

#define trace_preempt_enable_rcuidle(...)

#define trace_preempt_disable_rcuidle(...)

#endif

kernel/trace/trace_preemptirq.c

+6 −20
Original line number Diff line number Diff line
@@ -15,20 +15,6 @@ 
#define CREATE_TRACE_POINTS

#include <trace/events/preemptirq.h>



/*

 * Use regular trace points on architectures that implement noinstr

 * tooling: these calls will only happen with RCU enabled, which can

 * use a regular tracepoint.

 *

 * On older architectures, use the rcuidle tracing methods (which

 * aren't NMI-safe - so exclude NMI contexts):

 */

#ifdef CONFIG_ARCH_WANTS_NO_INSTR

#define trace(point)	trace_##point

#else

#define trace(point)	if (!in_nmi()) trace_##point##_rcuidle

#endif



#ifdef CONFIG_TRACE_IRQFLAGS

/* Per-cpu variable to prevent redundant calls when IRQs already off */

static DEFINE_PER_CPU(int, tracing_irq_cpu);
@@ -42,7 +28,7 @@ static DEFINE_PER_CPU(int, tracing_irq_cpu); 
void trace_hardirqs_on_prepare(void)

{

	if (this_cpu_read(tracing_irq_cpu)) {

		trace(irq_enable)(CALLER_ADDR0, CALLER_ADDR1);

		trace_irq_enable(CALLER_ADDR0, CALLER_ADDR1);

		tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);

		this_cpu_write(tracing_irq_cpu, 0);

	}
@@ -53,7 +39,7 @@ NOKPROBE_SYMBOL(trace_hardirqs_on_prepare); 
void trace_hardirqs_on(void)

{

	if (this_cpu_read(tracing_irq_cpu)) {

		trace(irq_enable)(CALLER_ADDR0, CALLER_ADDR1);

		trace_irq_enable(CALLER_ADDR0, CALLER_ADDR1);

		tracer_hardirqs_on(CALLER_ADDR0, CALLER_ADDR1);

		this_cpu_write(tracing_irq_cpu, 0);

	}
@@ -75,7 +61,7 @@ void trace_hardirqs_off_finish(void) 
	if (!this_cpu_read(tracing_irq_cpu)) {

		this_cpu_write(tracing_irq_cpu, 1);

		tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);

		trace(irq_disable)(CALLER_ADDR0, CALLER_ADDR1);

		trace_irq_disable(CALLER_ADDR0, CALLER_ADDR1);

	}



}
@@ -89,7 +75,7 @@ void trace_hardirqs_off(void) 
	if (!this_cpu_read(tracing_irq_cpu)) {

		this_cpu_write(tracing_irq_cpu, 1);

		tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);

		trace(irq_disable)(CALLER_ADDR0, CALLER_ADDR1);

		trace_irq_disable(CALLER_ADDR0, CALLER_ADDR1);

	}

}

EXPORT_SYMBOL(trace_hardirqs_off);
@@ -100,13 +86,13 @@ NOKPROBE_SYMBOL(trace_hardirqs_off); 


void trace_preempt_on(unsigned long a0, unsigned long a1)

{

	trace(preempt_enable)(a0, a1);

	trace_preempt_enable(a0, a1);

	tracer_preempt_on(a0, a1);

}



void trace_preempt_off(unsigned long a0, unsigned long a1)

{

	trace(preempt_disable)(a0, a1);

	trace_preempt_disable(a0, a1);

	tracer_preempt_off(a0, a1);

}

#endif

scripts/tags.sh

+0 −2
Original line number Diff line number Diff line
@@ -152,9 +152,7 @@ regex_c=( 
	'/^BPF_CALL_[0-9]([[:space:]]*\([[:alnum:]_]*\).*/\1/'

	'/^COMPAT_SYSCALL_DEFINE[0-9]([[:space:]]*\([[:alnum:]_]*\).*/compat_sys_\1/'

	'/^TRACE_EVENT([[:space:]]*\([[:alnum:]_]*\).*/trace_\1/'

	'/^TRACE_EVENT([[:space:]]*\([[:alnum:]_]*\).*/trace_\1_rcuidle/'

	'/^DEFINE_EVENT([^,)]*,[[:space:]]*\([[:alnum:]_]*\).*/trace_\1/'

	'/^DEFINE_EVENT([^,)]*,[[:space:]]*\([[:alnum:]_]*\).*/trace_\1_rcuidle/'

	'/^DEFINE_INSN_CACHE_OPS([[:space:]]*\([[:alnum:]_]*\).*/get_\1_slot/'

	'/^DEFINE_INSN_CACHE_OPS([[:space:]]*\([[:alnum:]_]*\).*/free_\1_slot/'

	'/^PAGEFLAG([[:space:]]*\([[:alnum:]_]*\).*/Page\1/'