extern void kvfree(const void *addr);
+/*
+ * Mapcount of compound page as a whole, does not include mapped sub-pages.
+ *
+ * Must be called only for compound pages or any their tail sub-pages.
+ */
static inline int compound_mapcount(struct page *page)
{
VM_BUG_ON_PAGE(!PageCompound(page), page);
int __page_mapcount(struct page *page);
+/*
+ * Mapcount of 0-order page; when compound sub-page, includes
+ * compound_mapcount().
+ *
+ * Result is undefined for pages which cannot be mapped into userspace.
+ * For example SLAB or special types of pages. See function page_has_type().
+ * They use this place in struct page differently.
+ */
static inline int page_mapcount(struct page *page)
{
- VM_BUG_ON_PAGE(PageSlab(page), page);
-
if (unlikely(PageCompound(page)))
return __page_mapcount(page);
return atomic_read(&page->_mapcount) + 1;
int __must_check write_one_page(struct page *page);
void task_dirty_inc(struct task_struct *tsk);
-/* readahead.c */
-#define VM_READAHEAD_PAGES (SZ_128K / PAGE_SIZE)
-
-int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
- pgoff_t offset, unsigned long nr_to_read);
-
-void page_cache_sync_readahead(struct address_space *mapping,
- struct file_ra_state *ra,
- struct file *filp,
- pgoff_t offset,
- unsigned long size);
-
-void page_cache_async_readahead(struct address_space *mapping,
- struct file_ra_state *ra,
- struct file *filp,
- struct page *pg,
- pgoff_t offset,
- unsigned long size);
-
extern unsigned long stack_guard_gap;
/* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */
extern int expand_stack(struct vm_area_struct *vma, unsigned long address);