When profiling the kernel with the 'srcfile' sort key it's common to
"get stuck" in include. For example a lot of code uses current or other
inlines, so they get accounted to some random include file. This is not
very useful as a high level categorization.

For example just profiling the idle loop usually shows mostly inlines,
so you never see the actual cpuidle file.

This patch changes the 'srcfile' sort key to always unwind the inline
stack using BFD/DWARF. So we always account to the base function that
called the inline.

In a few cases include is still shown (for example for MSR accesses),
but that is because they get inlining expanded as part of assigning to a
global function pointer. For the majority it works fine though.

v2: Use simpler while loop. Add maximum iteration count.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1441133239-31254-1-git-send-email-andi@firstfloor.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>