trace: Don't declare trace_*_rcuidle functions in modules (7ece55a4) · Commits · 戴 / test

Tracepoints declare a static inline trace_*_rcuidle variant of the trace function, to support safely generating trace events from the idle loop. Module code never actually uses that variant of trace functions, because modules don't run code that needs tracing with RCU idled. However, the declaration of those otherwise unused functions causes the module to reference rcu_idle_exit and rcu_idle_enter, which RCU does not export to modules. To avoid this, don't generate trace_*_rcuidle functions for tracepoints declared in module code. Link: http://lkml.kernel.org/r/20120905062306.GA14756@leaf Reported-by:

Steven Rostedt <rostedt@goodmis.org> Acked-by:

Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by:

Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by:

Josh Triplett <josh@joshtriplett.org> Signed-off-by:

Steven Rostedt <rostedt@goodmis.org>

include/linux/tracepoint.h

+18 −10

Original line number	Diff line number	Diff line
		@@ -136,6 +136,22 @@ static inline void tracepoint_synchronize_unregister(void)
		postrcu; \
		} while (0)

		#ifndef MODULE
		#define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args) \
		static inline void trace_##name##_rcuidle(proto) \
		{ \
		if (static_key_false(&__tracepoint_##name.key)) \
		__DO_TRACE(&__tracepoint_##name, \
		TP_PROTO(data_proto), \
		TP_ARGS(data_args), \
		TP_CONDITION(cond), \
		rcu_idle_exit(), \
		rcu_idle_enter()); \
		}
		#else
		#define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args)
		#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
		@@ -151,16 +167,8 @@ static inline void tracepoint_synchronize_unregister(void)
		TP_ARGS(data_args), \
		TP_CONDITION(cond),,); \
		} \
		static inline void trace_##name##_rcuidle(proto) \
		{ \
		if (static_key_false(&__tracepoint_##name.key)) \
		__DO_TRACE(&__tracepoint_##name, \
		TP_PROTO(data_proto), \
		TP_ARGS(data_args), \
		TP_CONDITION(cond), \
		rcu_idle_exit(), \
		rcu_idle_enter()); \
		} \
		__DECLARE_TRACE_RCU(name, PARAMS(proto), PARAMS(args), \
		PARAMS(cond), PARAMS(data_proto), PARAMS(data_args)) \
		static inline int \
		register_trace_##name(void (probe)(data_proto), void data) \
		{ \

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