Re: [Qemu-devel] [PATCH 0/2] improve tracing

[Lluís Vilanova]

Vladimir Sementsov-Ogievskiy writes:

> Current trace system have a drawback: parameters of trace functions
> are calculated even if corresponding tracepoint is disabled. Also, it
> looks like trace function are not actually inlined by compiler (at
> least for me).

> Here is a fix proposal: move from function call to macros. Patch 02
> is an example, of how to reduce extra calculations with help of
> patch 01.

The tracing functions *were* inlined last time I checked, although things
changed quite a lot since then. Not sure that will make a lot of difference in
terms of overall performance (needs measuring).

As for arguments, each trace event has a define TRACE_{NAME}_ENABLED that you
can use for that purpose. If this is not explained in tracing.txt, that is a
documentation bug.


Thanks,
  Lluis