On Mon, Dec 03, 2012 at 09:40:48AM -0500, Steven Rostedt wrote:

The issue is with x86. Gcc wont compile if you have -pg and
-fomit-frame-pointer on x86. I originally forced function tracing to
select FRAME_POINTER, but because now on x86 with -mfentry, -pg no
longer requires frame pointers being set, I just let -pg complain one
way or the other. I believe that gcc by default will not add frame
pointers. Thus adding function tracing just prevents
-fomit-frame-pointer from being set, and if -pg requires frame pointers
it will automatically enable them otherwise they should not be enabled.

On architectures such as MIPS where a frame pointer is not required for
debugging -O and higher imply -fomit-frame-pointer.

  Ralf