6  *  Swap reorganised 29.12.95, Stephen Tweedie
14 #include <linux/swap.h>
26 #include "swap.h"
68 	printk("%lu pages in swap cache\n", total_swapcache_pages());  in show_swap_cache_info()
69 	printk("Free swap  = %ldkB\n", K(get_nr_swap_pages()));  in show_swap_cache_info()
70 	printk("Total swap = %lukB\n", K(total_swap_pages));  in show_swap_cache_info()
87  * but sets SwapCache flag and 'swap' instead of mapping and index.
106 	folio->swap = entry;  in add_to_swap_cache()
140  * been verified to be in the swap cache.
162 	folio->swap.val = 0;  in __delete_from_swap_cache()
171  * been verified to be in the swap cache and locked.
177 	swp_entry_t entry = folio->swap;  in delete_from_swap_cache()
218  * If we are the only user, then try to free up the swap cache.
235  * Perform a free_page(), also freeing any swap cache associated with
279  * Lookup a swap entry in the swap cache. A found folio will be returned
284  * Caller must lock the swap device or hold a reference to keep it valid.
330  * filemap_get_incore_folio - Find and get a folio from the page or swap caches.
335  * folio in the swap cache.
381 		 * First check the swap cache.  Since this is normally  in __read_swap_cache_async()
391 		 * Just skip read ahead for unused swap slot.  in __read_swap_cache_async()
397 		 * Get a new folio to read into from swap.  Allocate it now if  in __read_swap_cache_async()
409 		 * Swap entry may have been freed since our caller observed it.  in __read_swap_cache_async()
420 		 * is set but the folio is not the swap cache yet. This can  in __read_swap_cache_async()
433 		 * in swap_map, but not yet added its folio to swap cache.  in __read_swap_cache_async()
439 	 * The swap entry is ours to swap in. Prepare the new folio.  in __read_swap_cache_async()
474  * Locate a page of swap in physical memory, reserving swap cache space
477  * the swap entry is no longer in use.
481  * swap cache folio lock.
527 		 * (and don't even bother to check whether swap type is same).  in __swapin_nr_pages()
571  * swap_cluster_readahead - swap in pages in hope we need them soon
572  * @entry: swap entry of this memory
579  * Primitive swap readahead code. We simply read an aligned block of
580  * (1 << page_cluster) entries in the swap area. This method is chosen
585  * are used for every page of the readahead: neighbouring pages on swap
608 	if (!start_offset)	/* First page is swap header. */  in swap_cluster_readahead()
656 		/* swap cache doesn't use writeback related tags */  in init_swap_address_space()
716  * swap_vma_readahead - swap in pages in hope we need them soon
717  * @targ_entry: swap entry of the targeted memory
725  * Primitive swap readahead code. We simply read in a few pages whose
793  * swapin_readahead - swap in pages in hope we need them soon
794  * @entry: swap entry of this memory
800  * It's a main entry function for swap readahead. By the configuration,
854 	swap_kobj = kobject_create_and_add("swap", mm_kobj);  in swap_init_sysfs()
856 		pr_err("failed to create swap kobject\n");  in swap_init_sysfs()
861 		pr_err("failed to register swap group\n");  in swap_init_sysfs()