hugetlbfs: handle pages higher order than MAX_ORDER

[linux-2.6-omap-h63xx.git] / mm / internal.h

diff --git a/mm/internal.h b/mm/internal.h
index 48e32f790571f8868e69771e2c91c8c2fd3a34ae..f482460de3e69b1f25c2e6fb97d15c1553516005 100644 (file)
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -101,7 +101,10 @@ static inline int is_mlocked_vma(struct vm_area_struct *vma, struct page *page)
        if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
                return 0;
 
-       SetPageMlocked(page);
+       if (!TestSetPageMlocked(page)) {
+               inc_zone_page_state(page, NR_MLOCK);
+               count_vm_event(UNEVICTABLE_PGMLOCKED);
+       }
        return 1;
 }
 
@@ -128,14 +131,37 @@ static inline void clear_page_mlock(struct page *page)
 
 /*
  * mlock_migrate_page - called only from migrate_page_copy() to
- * migrate the Mlocked page flag
+ * migrate the Mlocked page flag; update statistics.
  */
 static inline void mlock_migrate_page(struct page *newpage, struct page *page)
 {
-       if (TestClearPageMlocked(page))
+       if (TestClearPageMlocked(page)) {
+               unsigned long flags;
+
+               local_irq_save(flags);
+               __dec_zone_page_state(page, NR_MLOCK);
                SetPageMlocked(newpage);
+               __inc_zone_page_state(newpage, NR_MLOCK);
+               local_irq_restore(flags);
+       }
 }
 
+/*
+ * free_page_mlock() -- clean up attempts to free and mlocked() page.
+ * Page should not be on lru, so no need to fix that up.
+ * free_pages_check() will verify...
+ */
+static inline void free_page_mlock(struct page *page)
+{
+       if (unlikely(TestClearPageMlocked(page))) {
+               unsigned long flags;
+
+               local_irq_save(flags);
+               __dec_zone_page_state(page, NR_MLOCK);
+               __count_vm_event(UNEVICTABLE_MLOCKFREED);
+               local_irq_restore(flags);
+       }
+}
 
 #else /* CONFIG_UNEVICTABLE_LRU */
 static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
@@ -145,9 +171,38 @@ static inline int is_mlocked_vma(struct vm_area_struct *v, struct page *p)
 static inline void clear_page_mlock(struct page *page) { }
 static inline void mlock_vma_page(struct page *page) { }
 static inline void mlock_migrate_page(struct page *new, struct page *old) { }
+static inline void free_page_mlock(struct page *page) { }
 
 #endif /* CONFIG_UNEVICTABLE_LRU */
 
+/*
+ * Return the mem_map entry representing the 'offset' subpage within
+ * the maximally aligned gigantic page 'base'.  Handle any discontiguity
+ * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
+ */
+static inline struct page *mem_map_offset(struct page *base, int offset)
+{
+       if (unlikely(offset >= MAX_ORDER_NR_PAGES))
+               return pfn_to_page(page_to_pfn(base) + offset);
+       return base + offset;
+}
+
+/*
+ * Iterator over all subpages withing the maximally aligned gigantic
+ * page 'base'.  Handle any discontiguity in the mem_map.
+ */
+static inline struct page *mem_map_next(struct page *iter,
+                                               struct page *base, int offset)
+{
+       if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
+               unsigned long pfn = page_to_pfn(base) + offset;
+               if (!pfn_valid(pfn))
+                       return NULL;
+               return pfn_to_page(pfn);
+       }
+       return iter + 1;
+}
+
 /*
  * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node,
  * so all functions starting at paging_init should be marked __init