Messages in this thread | | | Subject | Re: [PATCH] Fix tracing infrastructure to support multiple includes when defining CREATE_TRACE_POINTS | From | Steven Rostedt <> | Date | Mon, 07 Dec 2009 15:04:42 -0500 |
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On Thu, 2009-12-03 at 14:35 -0500, Neil Horman wrote:
> Fix tracing infrastructure to allow multiple header files with TRACE_EVENTS to > be included with CREATE_TRACE_EVENTS defined > > I've been workingon adding a few tracepoints to the network stack, and in so > doing it was convienient for me to add a second include file to > net/core/net-traces.c with TRACE_EVENTS defined in them. net-traces.c defines > CREATE_TRACE_EVENTS, and during the build it was failing, complaining about > duplicate definitions of __tpstrtab_<name>. I tracked down the bug to find that > define_trace.h redefined DECLARE_TRACE to be DEFINE_TRACE, so after the first > run through define_trace.h (which is included from skb.h, included in > net-trace.c first), the DECLARE_TRACE macro was left with an improper definition > to start a new cycle with the next header. > > The fix I came up with was to make sure that DECLARE_TRACE was undefined at the > end of define_trace.h, and to add a conditional re-definition in tracepoint.h. > This places us back in the proper state to define a new set of tracepoints in a > subsequent header file. > > Signed-off-by: Neil Horman <nhorman@tuxdriver.com> >
By itself, this patch breaks the build (for me). I take it that you converted the napi.h file to use TRACE_EVENT. Currently it uses a DECLARE_TRACE, which will break with this patch. We need a patch that removes that DECLARE_TRACE before we can apply this patch.
To keep bisectablity, we either need to make one patch that converts the napi to TRACE_EVENT and this patch, or we need to first remove the napi.h DECLARE_TRACE, add this patch, and then one that adds TRACE_EVENT.
-- Steve
> diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h > index 2aac8a8..311abbf 100644 > --- a/include/linux/tracepoint.h > +++ b/include/linux/tracepoint.h > @@ -58,28 +58,6 @@ struct tracepoint { > rcu_read_unlock_sched_notrace(); \ > } while (0) > > -/* > - * Make sure the alignment of the structure in the __tracepoints section will > - * not add unwanted padding between the beginning of the section and the > - * structure. Force alignment to the same alignment as the section start. > - */ > -#define DECLARE_TRACE(name, proto, args) \ > - extern struct tracepoint __tracepoint_##name; \ > - static inline void trace_##name(proto) \ > - { \ > - if (unlikely(__tracepoint_##name.state)) \ > - __DO_TRACE(&__tracepoint_##name, \ > - TP_PROTO(proto), TP_ARGS(args)); \ > - } \ > - static inline int register_trace_##name(void (*probe)(proto)) \ > - { \ > - return tracepoint_probe_register(#name, (void *)probe); \ > - } \ > - static inline int unregister_trace_##name(void (*probe)(proto)) \ > - { \ > - return tracepoint_probe_unregister(#name, (void *)probe);\ > - } > - > > #define DEFINE_TRACE_FN(name, reg, unreg) \ > static const char __tpstrtab_##name[] \ > @@ -173,6 +151,29 @@ static inline void tracepoint_synchronize_unregister(void) > * trace event headers under one "CREATE_TRACE_POINTS" the first include > * will override the TRACE_EVENT and break the second include. > */ > +#if defined(CONFIG_TRACEPOINTS) && !defined(DECLARE_TRACE) > +/* > + * Make sure the alignment of the structure in the __tracepoints section will > + * not add unwanted padding between the beginning of the section and the > + * structure. Force alignment to the same alignment as the section start. > + */ > +#define DECLARE_TRACE(name, proto, args) \ > + extern struct tracepoint __tracepoint_##name; \ > + static inline void trace_##name(proto) \ > + { \ > + if (unlikely(__tracepoint_##name.state)) \ > + __DO_TRACE(&__tracepoint_##name, \ > + TP_PROTO(proto), TP_ARGS(args)); \ > + } \ > + static inline int register_trace_##name(void (*probe)(proto)) \ > + { \ > + return tracepoint_probe_register(#name, (void *)probe); \ > + } \ > + static inline int unregister_trace_##name(void (*probe)(proto)) \ > + { \ > + return tracepoint_probe_unregister(#name, (void *)probe);\ > + } > +#endif > > #ifndef TRACE_EVENT > /* > diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h > index 2a4b3bf..a3e0095 100644 > --- a/include/trace/define_trace.h > +++ b/include/trace/define_trace.h > @@ -64,6 +64,7 @@ > #undef TRACE_EVENT > #undef TRACE_EVENT_FN > #undef TRACE_HEADER_MULTI_READ > +#undef DECLARE_TRACE > > /* Only undef what we defined in this file */ > #ifdef UNDEF_TRACE_INCLUDE_FILE
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