mm,thp: stats for file backed THP

In preparation for non-shmem THP, this patch adds a few stats and exposes
them in /proc/meminfo, /sys/bus/node/devices/<node>/meminfo, and
/proc/<pid>/task/<tid>/smaps.

This patch is mostly a rewrite of Kirill A.  Shutemov's earlier version:
https://lkml.kernel.org/r/[email protected]/

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Song Liu <[email protected]>
Acked-by: Rik van Riel <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: William Kucharski <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions