Re: [PATCH -tip FIXED] ftrace: add nop tracer

["Steven Noonan" <steven@uplinklabs.net>]

On Fri, Sep 19, 2008 at 2:23 PM, Andrew Morton
<akpm@linux-foundation.org> wrote:
> On Fri, 19 Sep 2008 03:06:43 -0700
> Steven Noonan <steven@uplinklabs.net> wrote:
>
>> --- a/kernel/trace/trace.h
>> +++ b/kernel/trace/trace.h
>> @@ -339,6 +339,10 @@ extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
>>  extern int trace_selftest_startup_wakeup(struct tracer *trace,
>>                                        struct trace_array *tr);
>>  #endif
>> +#ifdef CONFIG_NOP_TRACER
>> +extern int trace_selftest_startup_nop(struct tracer *trace,
>> +                                      struct trace_array *tr);
>> +#endif
>>  #ifdef CONFIG_CONTEXT_SWITCH_TRACER
>>  extern int trace_selftest_startup_sched_switch(struct tracer *trace,
>>                                              struct trace_array *tr);
>
> Consider omitting the ifdefs around the declarations.
>
> pro: the code looks nicer and is less likely to suffer build errors
> with weird config combinations.
>
> con: build errors are reported at link-time rather than at compile-time.
>
> Personally, I think pro>con here.
>

I merely based this on one of the other tracers, so the ifdefs are
basically copied and renamed.