/proc/pid/smaps: fix dirty pages accounting
/proc/pid/smaps: fix dirty pages accounting

Currently, /proc/<pid>/smaps has wrong dirty pages accounting.
Shared_Dirty and Private_Dirty output only pte dirty pages and ignore
PG_dirty page flag.  It is difference against documentation, but also
inconsistent against Referenced field.  (Referenced checks both pte and
page flags)

This patch fixes it.

Test program:

 large-array.c
 ---------------------------------------------------
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>

 char array[1*1024*1024*1024L];

 int main(void)
 {
         memset(array, 1, sizeof(array));
         pause();

         return 0;
 }
 ---------------------------------------------------

Test case:
 1. run ./large-array
 2. cat /proc/`pidof large-array`/smaps
 3. swapoff -a
 4. cat /proc/`pidof large-array`/smaps again

Test result:
 <before patch>

00601000-40601000 rw-p 00000000 00:00 0
Size:            1048576 kB
Rss:             1048576 kB
Pss:             1048576 kB
Shared_Clean:          0 kB
Shared_Dirty:          0 kB
Private_Clean:    218992 kB   <-- showed pages as clean incorrectly
Private_Dirty:    829584 kB
Referenced:       388364 kB
Swap:                  0 kB
KernelPageSize:        4 kB
MMUPageSize:           4 kB

 <after patch>

00601000-40601000 rw-p 00000000 00:00 0
Size:            1048576 kB
Rss:             1048576 kB
Pss:             1048576 kB
Shared_Clean:          0 kB
Shared_Dirty:          0 kB
Private_Clean:         0 kB
Private_Dirty:   1048576 kB  <-- fixed
Referenced:       388480 kB
Swap:                  0 kB
KernelPageSize:        4 kB
MMUPageSize:           4 kB

Signed-off-by: KOSAKI Motohiro <70a1d3ef3e17a2bb0f09a1b2e6c86f607ed1d6d9@jp.fujitsu.com>
Acked-by: Hugh Dickins <d3abdf3e2800e6cb849f11b81e6eb50b34d96431@google.com>
Cc: Matt Mackall <4121265491a72225438dfd0e91a228f361407ae2@selenic.com>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas