1 files changed, 59 insertions, 0 deletions

diff --git a/mm/rmap.c b/mm/rmap.c
index 38a336e2eea1..0ad53572eaf2 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -56,6 +56,7 @@
 #include <linux/memcontrol.h>
 #include <linux/mmu_notifier.h>
 #include <linux/migrate.h>
+#include <linux/hugetlb.h>
 
 #include <asm/tlbflush.h>
 
@@ -326,6 +327,8 @@ vma_address(struct page *page, struct vm_area_struct *vma)
         pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
         unsigned long address;
 
+        if (unlikely(is_vm_hugetlb_page(vma)))
+                pgoff = page->index << huge_page_order(page_hstate(page));
         address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
         if (unlikely(address < vma->vm_start || address >= vma->vm_end)) {
                 /* page should be within @vma mapping range */
@@ -369,6 +372,12 @@ pte_t *page_check_address(struct page *page, struct mm_struct *mm,
         pte_t *pte;
         spinlock_t *ptl;
 
+        if (unlikely(PageHuge(page))) {
+                pte = huge_pte_offset(mm, address);
+                ptl = &mm->page_table_lock;
+                goto check;
+        }
+
         pgd = pgd_offset(mm, address);
         if (!pgd_present(*pgd))
                 return NULL;
@@ -389,6 +398,7 @@ pte_t *page_check_address(struct page *page, struct mm_struct *mm,
         }
 
         ptl = pte_lockptr(mm, pmd);
+check:
         spin_lock(ptl);
         if (pte_present(*pte) && page_to_pfn(page) == pte_pfn(*pte)) {
                 *ptlp = ptl;
@@ -873,6 +883,12 @@ void page_remove_rmap(struct page *page)
                 page_clear_dirty(page);
                 set_page_dirty(page);
         }
+        /*
+         * Hugepages are not counted in NR_ANON_PAGES nor NR_FILE_MAPPED
+         * and not charged by memcg for now.
+         */
+        if (unlikely(PageHuge(page)))
+                return;
         if (PageAnon(page)) {
                 mem_cgroup_uncharge_page(page);
                 __dec_zone_page_state(page, NR_ANON_PAGES);
@@ -1445,3 +1461,46 @@ int rmap_walk(struct page *page, int (*rmap_one)(struct page *,
                 return rmap_walk_file(page, rmap_one, arg);
 }
 #endif /* CONFIG_MIGRATION */
+
+#ifdef CONFIG_HUGETLBFS
+/*
+ * The following three functions are for anonymous (private mapped) hugepages.
+ * Unlike common anonymous pages, anonymous hugepages have no accounting code
+ * and no lru code, because we handle hugepages differently from common pages.
+ */
+static void __hugepage_set_anon_rmap(struct page *page,
+        struct vm_area_struct *vma, unsigned long address, int exclusive)
+{
+        struct anon_vma *anon_vma = vma->anon_vma;
+        BUG_ON(!anon_vma);
+        if (!exclusive) {
+                struct anon_vma_chain *avc;
+                avc = list_entry(vma->anon_vma_chain.prev,
+                                 struct anon_vma_chain, same_vma);
+                anon_vma = avc->anon_vma;
+        }
+        anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
+        page->mapping = (struct address_space *) anon_vma;
+        page->index = linear_page_index(vma, address);
+}
+
+void hugepage_add_anon_rmap(struct page *page,
+                            struct vm_area_struct *vma, unsigned long address)
+{
+        struct anon_vma *anon_vma = vma->anon_vma;
+        int first;
+        BUG_ON(!anon_vma);
+        BUG_ON(address < vma->vm_start || address >= vma->vm_end);
+        first = atomic_inc_and_test(&page->_mapcount);
+        if (first)
+                __hugepage_set_anon_rmap(page, vma, address, 0);
+}
+
+void hugepage_add_new_anon_rmap(struct page *page,
+                        struct vm_area_struct *vma, unsigned long address)
+{
+        BUG_ON(address < vma->vm_start || address >= vma->vm_end);
+        atomic_set(&page->_mapcount, 0);
+        __hugepage_set_anon_rmap(page, vma, address, 1);
+}
+#endif /* CONFIG_HUGETLBFS */