Re: bug: ftrace & lockdep badness

["Frédéric Weisbecker" <fweisbec@gmail.com>]

2008/11/5 Steven Rostedt <rostedt@goodmis.org>:
> I do like the fact that lockdep checks it too. But there's times that we
> can not do that.
>
> Perhaps we can do something in between.
>
> Make a rb_spin_lock macro inside ring_buffer.c that can be either a
> spin_lock or a raw_spin_lock.  There are some tracers that must have this
> as a raw (function trace, irqsoff and preemptoff), but the rest should be
> fine. We can make it where the rb_spin_lock is a raw lock when any of
> those three tracers are configured, and make it into a normal lock when
> they are not.


But this way we won't be able to have lockdep checks when only one of
those "raw-need" tracers are
configured. Wouldn't it better to set it as a function pointer? It
would dynamically reference spin_lock or
raw_spin_lock functions depending on what tracer is currently
selected. I think that wouldn't hardly impact
the performances....