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 15:47:11 -0500 |
| |
On Mon, 2009-12-07 at 15:18 -0500, Neil Horman wrote: > On Mon, Dec 07, 2009 at 03:04:42PM -0500, Steven Rostedt wrote: > > 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. > > > Yes, I did that conversion, sorry, wasn't thinking about how that might affect > the build. Given that converting to a TRACE_EVENT shouldn't be noticible to any > of the users of that tracepoint (it can still be hooked in an identical > fashion), I'd vote for just doing a monolitic patch. please find that below. > > Regards > Neil > > > > 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. > > > Note this patch also converts the napi_poll tracepoint to a TRACE_EVENT. This > is done so that the TRACE_EVENT fix doesn't break the build, and because its > rather pointless I think given the current tracing infrastructure to not have > napi_poll be an independent event. > > Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Thanks, I'll give it a test. But because this now touches networking code, I need an Acked-by from David Miller before I can pull it in.
-- Steve
> > > linux/tracepoint.h | 45 +++++++++++++++++++++++---------------------- > trace/define_trace.h | 1 + > trace/events/napi.h | 25 ++++++++++++++++++++++--- > 3 files changed, 46 insertions(+), 25 deletions(-) > > 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 > diff --git a/include/trace/events/napi.h b/include/trace/events/napi.h > index a8989c4..25a1709 100644 > --- a/include/trace/events/napi.h > +++ b/include/trace/events/napi.h > @@ -1,11 +1,30 @@ > -#ifndef _TRACE_NAPI_H_ > +#undef TRACE_SYSTEM > +#define TRACE_SYSTEM napi > + > +#if !defined(_TRACE_NAPI_H_) || defined(TRACE_HEADER_MULTI_READ) > #define _TRACE_NAPI_H_ > > #include <linux/netdevice.h> > #include <linux/tracepoint.h> > > -DECLARE_TRACE(napi_poll, > +TRACE_EVENT(napi_poll, > + > TP_PROTO(struct napi_struct *napi), > - TP_ARGS(napi)); > + > + TP_ARGS(napi), > + > + TP_STRUCT__entry( > + __field( struct napi_struct *, napi) > + ), > + > + TP_fast_assign( > + __entry->napi = napi; > + ), > + > + TP_printk("napi poll on napi struct %p for device %s", > + __entry->napi, __entry->napi->dev->name) > +); > > #endif > + > +#include <trace/define_trace.h>
| |