交换空间全部交换空间都只有一个address_space来表示？

tacoee

810 static inline struct address_space *page_mapping(struct page *page)
811 {
812     struct address_space *mapping = page->mapping;
813
814     VM_BUG_ON(PageSlab(page));
815     if (unlikely(PageSwapCache(page)))
816         mapping = &swapper_space;
817     else if ((unsigned long)mapping & PAGE_MAPPING_ANON)
818         mapping = NULL;
819     return mapping;
820 }


&swapper_space;　只有一个全局的这个结构。

40 struct address_space swapper_space = {
41     .page_tree  = RADIX_TREE_INIT(GFP_ATOMIC|__GFP_NOWARN),
42     .tree_lock  = __SPIN_LOCK_UNLOCKED(swapper_space.tree_lock),
43     .a_ops      = &swap_aops,
44     .i_mmap_nonlinear = LIST_HEAD_INIT(swapper_space.i_mmap_nonlinear),
45     .backing_dev_info = &swap_backing_dev_info,
46 };
47