mm: pack compound_dtor and compound_order into one word in struct page

[linux-2.6-block.git] / include / linux / mm.h

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 80001de019ba33d86b90b9922b39722270cb0449..6581c21320cbb67819a057553c50aec969c8a962 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -139,6 +139,7 @@ extern unsigned int kobjsize(const void *objp);
 
 #define VM_DONTCOPY    0x00020000      /* Do not copy this vma on fork */
 #define VM_DONTEXPAND  0x00040000      /* Cannot expand with mremap() */
+#define VM_LOCKONFAULT 0x00080000      /* Lock the pages covered when they are faulted in */
 #define VM_ACCOUNT     0x00100000      /* Is a VM accounted object */
 #define VM_NORESERVE   0x00200000      /* should the VM suppress accounting */
 #define VM_HUGETLB     0x00400000      /* Huge TLB Page VM */
@@ -202,6 +203,9 @@ extern unsigned int kobjsize(const void *objp);
 /* This mask defines which mm->def_flags a process can inherit its parent */
 #define VM_INIT_DEF_MASK       VM_NOHUGEPAGE
 
+/* This mask is used to clear all the VMA flags used by mlock */
+#define VM_LOCKED_CLEAR_MASK   (~(VM_LOCKED | VM_LOCKONFAULT))
+
 /*
  * mapping from the currently active vm_flags protection bits (the
  * low four bits) to a page protection mask..
@@ -564,18 +568,32 @@ int split_free_page(struct page *page);
 /*
  * Compound pages have a destructor function.  Provide a
  * prototype for that function and accessor functions.
- * These are _only_ valid on the head of a PG_compound page.
+ * These are _only_ valid on the head of a compound page.
  */
+typedef void compound_page_dtor(struct page *);
+
+/* Keep the enum in sync with compound_page_dtors array in mm/page_alloc.c */
+enum compound_dtor_id {
+       NULL_COMPOUND_DTOR,
+       COMPOUND_PAGE_DTOR,
+#ifdef CONFIG_HUGETLB_PAGE
+       HUGETLB_PAGE_DTOR,
+#endif
+       NR_COMPOUND_DTORS,
+};
+extern compound_page_dtor * const compound_page_dtors[];
 
 static inline void set_compound_page_dtor(struct page *page,
-                                               compound_page_dtor *dtor)
+               enum compound_dtor_id compound_dtor)
 {
-       page[1].compound_dtor = dtor;
+       VM_BUG_ON_PAGE(compound_dtor >= NR_COMPOUND_DTORS, page);
+       page[1].compound_dtor = compound_dtor;
 }
 
 static inline compound_page_dtor *get_compound_page_dtor(struct page *page)
 {
-       return page[1].compound_dtor;
+       VM_BUG_ON_PAGE(page[1].compound_dtor >= NR_COMPOUND_DTORS, page);
+       return compound_page_dtors[page[1].compound_dtor];
 }
 
 static inline int compound_order(struct page *page)
@@ -585,7 +603,7 @@ static inline int compound_order(struct page *page)
        return page[1].compound_order;
 }
 
-static inline void set_compound_order(struct page *page, unsigned long order)
+static inline void set_compound_order(struct page *page, unsigned int order)
 {
        page[1].compound_order = order;
 }
@@ -1606,8 +1624,10 @@ static inline void pgtable_init(void)
 
 static inline bool pgtable_page_ctor(struct page *page)
 {
+       if (!ptlock_init(page))
+               return false;
        inc_zone_page_state(page, NR_PAGETABLE);
-       return ptlock_init(page);
+       return true;
 }
 
 static inline void pgtable_page_dtor(struct page *page)
@@ -2036,8 +2056,6 @@ void page_cache_async_readahead(struct address_space *mapping,
                                pgoff_t offset,
                                unsigned long size);
 
-unsigned long max_sane_readahead(unsigned long nr);
-
 /* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */
 extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
 
@@ -2137,6 +2155,7 @@ static inline struct page *follow_page(struct vm_area_struct *vma,
 #define FOLL_NUMA      0x200   /* force NUMA hinting page fault */
 #define FOLL_MIGRATION 0x400   /* wait for page to replace migration entry */
 #define FOLL_TRIED     0x800   /* a retry, previous pass started an IO */
+#define FOLL_MLOCK     0x1000  /* lock present pages */
 
 typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
                        void *data);