[RFC][PATCH 0/4] tracing: Allow function tracing to start earlier in boot up

[Steven Rostedt]

I've had people ask about moving tracing up further in the boot process.
This patch series looks at function tracing only. It allows for tracing
(and function filtering) to be moved right after memory is initialized.
To have it happen before memory initialization would require a bit more
work with allocating the ring buffer. But this is a start.

I placed a hook into free_reserved_area() which is used by all archs
to free the init memory. Having it pass the range being freed to ftrace
lets ftrace clean up any function that is registered such that it doesn't
try to modify code that no longer exists. 


Steven Rostedt (VMware) (4):
      tracing: Split tracing initialization into two for early initialization
      ftrace: Move ftrace_init() to right after memory initialization
      ftrace: Have function tracing start in early boot up
      ftrace: Allow for function tracing to record init functions on boot up

----
 include/linux/ftrace.h         |  5 +++++
 include/linux/init.h           |  4 +++-
 init/main.c                    |  9 ++++++---
 kernel/trace/ftrace.c          | 44 ++++++++++++++++++++++++++++++++++++++++++
 kernel/trace/trace.c           |  9 ++++++++-
 kernel/trace/trace.h           |  2 ++
 kernel/trace/trace_functions.c |  3 +--
 mm/page_alloc.c                |  4 ++++
 scripts/recordmcount.c         |  1 +
 scripts/recordmcount.pl        |  1 +
 10 files changed, 75 insertions(+), 7 deletions(-)