Performance probes

[Alan DeKok]

Phil Mayers wrote:
> Would a patch adding dtrace/systemtap-compatible source probes be looked
> upon favourably?

  Yes.

> I'm fiddling with the debuginfo-based stap stuff to try and get a
> histogram of our ntlm_auth timings, but it strikes me that the
> source-based stuff could be very useful indeed; in particular
> appropriate DTRACE_PROBEx statements could let us time individual
> requests from receive to reply, with minimal performance overhead.

  That would be great.  I previously had patches to do this without
dtrace, but the patches were a bit invasive, and they had performance
impact.

  Alan DeKok.