account for huge pages about ps_mem HOT 2 CLOSED

Very good background as usual from https://lwn.net/Articles/423584/
I've asked for the huge page accounting to be split to private/shared in the lkml thread above.

Summary at this stage is that older non transparent huge pages
managed through hugetlbfs will be accounted for in the new smaps fields: {Private,Shared}_HugetlbPages
Note RH notes for accounting for this mem at: http://serverfault.com/questions/527085/linux-non-transparent-per-process-hugepage-accounting

The newer THP mechanism is already accounted for using the AnonHugePages smaps field,
and I've asked as to whether this is already accounted for in other {Private,Shared} fields,
or if it needs splitting itself to {Private,Shared} fields.

Note if all separate huge pages accounting will be done in {Private,Shared}_... fields,
then the current ps_mem logic will use that automatically

from ps_mem.

@Naoya-Horiguchi has updated so that {Private,Shared}_... now incorporates everything
https://lkml.org/lkml/2015/9/17/147
https://lkml.org/lkml/2015/9/17/179

from ps_mem.