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. Reported-by: Steven Rostedt <rost...@goodmis.org> Signed-off-by: Josh Triplett <j...@joshtriplett.org> --- On Tue, Sep 04, 2012 at 07:46:42PM -0400, Steven Rostedt wrote: > We could add either. Probably keep the ugliness of tracepoints inside > the tracepoint code than to start spreading it around to rcu. RCU has > its own ugliness features ;-) > > Hence, I would be OK if you send me a patch that does what you proposed > and removes the EXPORT from RCU. include/linux/tracepoint.h | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 802de56..2f322c3 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -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) \ { \ -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/