Dne 24.03.09 22:31, Robert Lor napsal(a):
> I think the is-enabled test will address the issues you encountered. I
> see a few alternative to fixing this:
>
> 1) Only use if (foo_ENABLED()) test for probes with expensive function
> call/computation in arguments. This will keep the code clean, and we can
> document this in the "Definine New Probes" section in the online doc.
>
> 2) Add the if(foo_ENABLED()) test to all probes manually and make this a
> requirement for all future probes. This makes the check explicit and
> avoid confusion.
>
> 3) Post-process probes.h so if(foo_ENABLED()) test is added to every
> probe. We're doing some post-processing now by pre-pending TRACE_ to the
> macros with a sed script. Personally, I don't like doing complex
> post-processing of output from another tool because the script can break
> if for some reason DTrace's output is changed.
>
> I prefer option 1 the most and 3 the least.
I prefer also option 1. In many cases if(foo_ENABLED) has same or bigger performance penalty like disabled probe
itself.
Zdenek
