thp: fix anon memory statistics with transparent hugepages

Count each transparent hugepage as HPAGE_PMD_NR pages in the LRU
statistics, so the Active(anon) and Inactive(anon) statistics in
/proc/meminfo are correct.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 5 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index f5b762ae23a2..0882014d2ce5 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1045,7 +1045,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
                 case 0:
                         list_move(&page->lru, dst);
                         mem_cgroup_del_lru(page);
-                        nr_taken++;
+                        nr_taken += hpage_nr_pages(page);
                         break;
 
                 case -EBUSY:
@@ -1103,7 +1103,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
                         if (__isolate_lru_page(cursor_page, mode, file) == 0) {
                                 list_move(&cursor_page->lru, dst);
                                 mem_cgroup_del_lru(cursor_page);
-                                nr_taken++;
+                                nr_taken += hpage_nr_pages(page);
                                 nr_lumpy_taken++;
                                 if (PageDirty(cursor_page))
                                         nr_lumpy_dirty++;
@@ -1158,14 +1158,15 @@ static unsigned long clear_active_flags(struct list_head *page_list,
         struct page *page;
 
         list_for_each_entry(page, page_list, lru) {
+                int numpages = hpage_nr_pages(page);
                 lru = page_lru_base_type(page);
                 if (PageActive(page)) {
                         lru += LRU_ACTIVE;
                         ClearPageActive(page);
-                        nr_active++;
+                        nr_active += numpages;
                 }
                 if (count)
-                        count[lru]++;
+                        count[lru] += numpages;
         }
 
         return nr_active;
@@ -1483,7 +1484,7 @@ static void move_active_pages_to_lru(struct zone *zone,
 
                 list_move(&page->lru, &zone->lru[lru].list);
                 mem_cgroup_add_lru_list(page, lru);
-                pgmoved++;
+                pgmoved += hpage_nr_pages(page);
 
                 if (!pagevec_add(&pvec, page) || list_empty(list)) {
                         spin_unlock_irq(&zone->lru_lock);