This interface is primarily useful for doing memory profiling and not much use

This interface is primarily useful for doing memory profiling and not much use
on deployed embedded boxes.  Make it optional.  Together with
/proc/pid/clear_refs, this save a few K.

Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/proc/base.c     |    4 ++++
 fs/proc/task_mmu.c |    2 ++
 init/Kconfig       |    8 ++++++++
 3 files changed, 14 insertions(+)