mm: catch memory commitment underflow
mm: catch memory commitment underflow

Print a warning (if CONFIG_DEBUG_VM=y) when memory commitment becomes
too negative.

This shouldn't happen any more - the previous two patches fixed the
committed_as underflow issues.

[5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org: use VM_WARN_ONCE, per Dave]
Signed-off-by: Konstantin Khlebnikov <313328defca653cd422fb17d20c38cc0fb4b890b@gmail.com>
Cc: Hugh Dickins <d3abdf3e2800e6cb849f11b81e6eb50b34d96431@google.com>
Cc: Dave Hansen <71bcd3d88361b22cd828f9a350d19d8775f56d4e@intel.com>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs