Re: [RFC] tracefs

Frederic Weisbecker
2009-10-23T09:38:39Z

On Fri, Oct 23, 2009 at 07:32:37AM +0200, Ingo Molnar wrote:
>
> * Greg KH <greg@kroah.com> wrote:
>
> > Hi all,
> >
> > At LinuxCon this year, Steven and I talked about moving the debugfs
> > usage in the tracing core to a stand-alone filesystem to give the
> > ability to start to lock down the api so that people an count on what
> > is going on in the tracing userspace interface.
>
> What we want to move out initially (and i talked to Steve and Frederic
> about that a few weeks ago) is the event description bits - the format
> stuff in /debug/tracing/events/ - but definitely not all the other,
> rather messy and ad-hoc APIs.
>
> _No way_ do we want to tie down the pretty-printing ftrace details as an
> ABI. We promised that when ftrace went upstream and all the details are
> way too messy to be exposed in an ABI alike matter (and yes, consider
> this a NAK Steve ;-).
>
> We want a _very_ careful exporting of certain pieces of information that
> helps syscall-exposed perf events bits, and to improve the quality of
> interfaces while we do that.
>
> Ingo

I guess the first bits that need to be exported are the TRACE_EVENT_ABI.
But even before that, we need to ensure we have a final version of
the trace events description.