6  *  Swap reorganised 29.12.95, Stephen Tweedie
13 #include <linux/swap.h>
75 	printk("%lu pages in swap cache\n", total_swapcache_pages());  in show_swap_cache_info()
76 	printk("Swap cache stats: add %lu, delete %lu, find %lu/%lu\n",  in show_swap_cache_info()
79 	printk("Free swap  = %ldkB\n",  in show_swap_cache_info()
81 	printk("Total swap = %lukB\n", total_swap_pages << (PAGE_SHIFT - 10));  in show_swap_cache_info()
150  * been verified to be in the swap cache.
178  * add_to_swap - allocate swap space for a page
179  * @page: page we want to move to swap
181  * Allocate swap space for the page and add the page to the
182  * swap cache.  Caller needs to hold the page lock. 
202 	 * deadlock in the swap out path.  in add_to_swap()
205 	 * Add it to the swap cache.  in add_to_swap()
222 	 * is swap in later. Always setting the dirty bit for the page solves  in add_to_swap()
236  * been verified to be in the swap cache and locked.
282  * If we are the only user, then try to free up the swap cache. 
298  * Perform a free_page(), also freeing any swap cache associated with
329  * Lookup a swap entry in the swap cache. A found page will be returned
384  * find_get_incore_page - Find and get a page from the page or swap caches.
389  * page in the swap cache.
430 		 * First check the swap cache.  Since this is normally  in __read_swap_cache_async()
444 		 * Just skip read ahead for unused swap slot.  in __read_swap_cache_async()
447 		 * swap entry in swap cache and marking swap slot  in __read_swap_cache_async()
455 		 * Get a new page to read into from swap.  Allocate it now,  in __read_swap_cache_async()
464 		 * Swap entry may have been freed since our caller observed it.  in __read_swap_cache_async()
479 		 * in swap_map, but not yet added its page to swap cache.  in __read_swap_cache_async()
485 	 * The swap entry is ours to swap in. Prepare the new page.  in __read_swap_cache_async()
516  * Locate a page of swap in physical memory, reserving swap cache space
519  * the swap entry is no longer in use.
552 		 * (and don't even bother to check whether swap type is same).  in __swapin_nr_pages()
596  * swap_cluster_readahead - swap in pages in hope we need them soon
597  * @entry: swap entry of this memory
603  * Primitive swap readahead code. We simply read an aligned block of
604  * (1 << page_cluster) entries in the swap area. This method is chosen
635 	if (!start_offset)	/* First page is swap header. */  in swap_cluster_readahead()
678 		/* swap cache doesn't use writeback related tags */  in init_swap_address_space()
775  * swap_vma_readahead - swap in pages in hope we need them soon
776  * @fentry: swap entry of this memory
782  * Primitive swap readahead code. We simply read in a few pages whose
838  * swapin_readahead - swap in pages in hope we need them soon
839  * @entry: swap entry of this memory
845  * It's a main entry function for swap readahead. By the configuration,
895 	swap_kobj = kobject_create_and_add("swap", mm_kobj);  in swap_init_sysfs()
897 		pr_err("failed to create swap kobject\n");  in swap_init_sysfs()
902 		pr_err("failed to register swap group\n");  in swap_init_sysfs()