mm/vmscan: add page demotion counter

Account the number of demoted pages.

Add pgdemote_kswapd and pgdemote_direct VM counters showed in
/proc/vmstat.

[ daveh:
   - __count_vm_events() a bit, and made them look at the THP
     size directly rather than getting data from migrate_pages()
]

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Yang Shi <[email protected]>
Signed-off-by: Dave Hansen <[email protected]>
Signed-off-by: "Huang, Ying" <[email protected]>
Reviewed-by: Yang Shi <[email protected]>
Reviewed-by: Wei Xu <[email protected]>
Reviewed-by: Zi Yan <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Greg Thelen <[email protected]>
Cc: Keith Busch <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions