1 files changed, 31 insertions, 17 deletions

diff --git a/mm/rmap.c b/mm/rmap.c
index 622756c16ac8..c330f9aba63a 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1133,6 +1133,7 @@ static void __page_check_anon_rmap(struct page *page,
  * @page:	the page to add the mapping to
  * @vma:	the vm area in which the mapping is added
  * @address:	the user virtual address mapped
+ * @compound:	charge the page as compound or small page
  *
  * The caller needs to hold the pte lock, and the page must be locked in
  * the anon_vma case: to serialize mapping,index checking after setting,
@@ -1140,9 +1141,9 @@ static void __page_check_anon_rmap(struct page *page,
  * (but PageKsm is never downgraded to PageAnon).
  */
 void page_add_anon_rmap(struct page *page,
-	struct vm_area_struct *vma, unsigned long address)
+	struct vm_area_struct *vma, unsigned long address, bool compound)
 {
-	do_page_add_anon_rmap(page, vma, address, 0);
+	do_page_add_anon_rmap(page, vma, address, compound ? RMAP_COMPOUND : 0);
 }
 
 /*
@@ -1151,21 +1152,24 @@ void page_add_anon_rmap(struct page *page,
  * Everybody else should continue to use page_add_anon_rmap above.
  */
 void do_page_add_anon_rmap(struct page *page,
-	struct vm_area_struct *vma, unsigned long address, int exclusive)
+	struct vm_area_struct *vma, unsigned long address, int flags)
 {
 	int first = atomic_inc_and_test(&page->_mapcount);
 	if (first) {
+		bool compound = flags & RMAP_COMPOUND;
+		int nr = compound ? hpage_nr_pages(page) : 1;
 		/*
 		 * We use the irq-unsafe __{inc|mod}_zone_page_stat because
 		 * these counters are not modified in interrupt context, and
 		 * pte lock(a spinlock) is held, which implies preemption
 		 * disabled.
 		 */
-		if (PageTransHuge(page))
+		if (compound) {
+			VM_BUG_ON_PAGE(!PageTransHuge(page), page);
 			__inc_zone_page_state(page,
 					      NR_ANON_TRANSPARENT_HUGEPAGES);
-		__mod_zone_page_state(page_zone(page), NR_ANON_PAGES,
-				hpage_nr_pages(page));
+		}
+		__mod_zone_page_state(page_zone(page), NR_ANON_PAGES, nr);
 	}
 	if (unlikely(PageKsm(page)))
 		return;
@@ -1173,7 +1177,8 @@ void do_page_add_anon_rmap(struct page *page,
 	VM_BUG_ON_PAGE(!PageLocked(page), page);
 	/* address might be in next vma when migration races vma_adjust */
 	if (first)
-		__page_set_anon_rmap(page, vma, address, exclusive);
+		__page_set_anon_rmap(page, vma, address,
+				flags & RMAP_EXCLUSIVE);
 	else
 		__page_check_anon_rmap(page, vma, address);
 }
@@ -1183,21 +1188,25 @@ void do_page_add_anon_rmap(struct page *page,
  * @page:	the page to add the mapping to
  * @vma:	the vm area in which the mapping is added
  * @address:	the user virtual address mapped
+ * @compound:	charge the page as compound or small page
  *
  * Same as page_add_anon_rmap but must only be called on *new* pages.
  * This means the inc-and-test can be bypassed.
  * Page does not have to be locked.
  */
 void page_add_new_anon_rmap(struct page *page,
-	struct vm_area_struct *vma, unsigned long address)
+	struct vm_area_struct *vma, unsigned long address, bool compound)
 {
+	int nr = compound ? hpage_nr_pages(page) : 1;
+
 	VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma);
 	SetPageSwapBacked(page);
 	atomic_set(&page->_mapcount, 0); /* increment count (starts at -1) */
-	if (PageTransHuge(page))
+	if (compound) {
+		VM_BUG_ON_PAGE(!PageTransHuge(page), page);
 		__inc_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES);
-	__mod_zone_page_state(page_zone(page), NR_ANON_PAGES,
-			hpage_nr_pages(page));
+	}
+	__mod_zone_page_state(page_zone(page), NR_ANON_PAGES, nr);
 	__page_set_anon_rmap(page, vma, address, 1);
 }
 
@@ -1249,13 +1258,17 @@ out:
 
 /**
  * page_remove_rmap - take down pte mapping from a page
- * @page: page to remove mapping from
+ * @page:	page to remove mapping from
+ * @compound:	uncharge the page as compound or small page
  *
  * The caller needs to hold the pte lock.
  */
-void page_remove_rmap(struct page *page)
+void page_remove_rmap(struct page *page, bool compound)
 {
+	int nr = compound ? hpage_nr_pages(page) : 1;
+
 	if (!PageAnon(page)) {
+		VM_BUG_ON_PAGE(compound && !PageHuge(page), page);
 		page_remove_file_rmap(page);
 		return;
 	}
@@ -1273,11 +1286,12 @@ void page_remove_rmap(struct page *page)
 	 * these counters are not modified in interrupt context, and
 	 * pte lock(a spinlock) is held, which implies preemption disabled.
 	 */
-	if (PageTransHuge(page))
+	if (compound) {
+		VM_BUG_ON_PAGE(!PageTransHuge(page), page);
 		__dec_zone_page_state(page, NR_ANON_TRANSPARENT_HUGEPAGES);
+	}
 
-	__mod_zone_page_state(page_zone(page), NR_ANON_PAGES,
-			      -hpage_nr_pages(page));
+	__mod_zone_page_state(page_zone(page), NR_ANON_PAGES, -nr);
 
 	if (unlikely(PageMlocked(page)))
 		clear_page_mlock(page);
@@ -1416,7 +1430,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
 	} else
 		dec_mm_counter(mm, mm_counter_file(page));
 
-	page_remove_rmap(page);
+	page_remove_rmap(page, PageHuge(page));
 	page_cache_release(page);
 
 out_unmap: