6  *  Swap reorganised 29.12.95, Stephen Tweedie
13 #include <linux/swap.h>
26 #include "swap.h"
66 	printk("%lu pages in swap cache\n", total_swapcache_pages());  in show_swap_cache_info()
67 	printk("Free swap  = %ldkB\n",  in show_swap_cache_info()
69 	printk("Total swap = %lukB\n", total_swap_pages << (PAGE_SHIFT - 10));  in show_swap_cache_info()
137  * been verified to be in the swap cache.
165  * add_to_swap - allocate swap space for a folio
166  * @folio: folio we want to move to swap
168  * Allocate swap space for the folio and add the folio to the
169  * swap cache.
172  * Return: Whether the folio was added to the swap cache.
192 	 * deadlock in the swap out path.  in add_to_swap()
195 	 * Add it to the swap cache.  in add_to_swap()
227  * been verified to be in the swap cache and locked.
273  * If we are the only user, then try to free up the swap cache. 
292  * Perform a free_page(), also freeing any swap cache associated with
323  * Lookup a swap entry in the swap cache. A found folio will be returned
376  * find_get_incore_page - Find and get a page from the page or swap caches.
381  * page in the swap cache.
425 		 * First check the swap cache.  Since this is normally  in __read_swap_cache_async()
439 		 * Just skip read ahead for unused swap slot.  in __read_swap_cache_async()
442 		 * swap entry in swap cache and marking swap slot  in __read_swap_cache_async()
450 		 * Get a new page to read into from swap.  Allocate it now,  in __read_swap_cache_async()
459 		 * Swap entry may have been freed since our caller observed it.  in __read_swap_cache_async()
474 		 * in swap_map, but not yet added its page to swap cache.  in __read_swap_cache_async()
480 	 * The swap entry is ours to swap in. Prepare the new page.  in __read_swap_cache_async()
511  * Locate a page of swap in physical memory, reserving swap cache space
514  * the swap entry is no longer in use.
549 		 * (and don't even bother to check whether swap type is same).  in __swapin_nr_pages()
593  * swap_cluster_readahead - swap in pages in hope we need them soon
594  * @entry: swap entry of this memory
600  * Primitive swap readahead code. We simply read an aligned block of
601  * (1 << page_cluster) entries in the swap area. This method is chosen
633 	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
839  * swapin_readahead - swap in pages in hope we need them soon
840  * @entry: swap entry of this memory
846  * It's a main entry function for swap readahead. By the configuration,
893 	swap_kobj = kobject_create_and_add("swap", mm_kobj);  in swap_init_sysfs()
895 		pr_err("failed to create swap kobject\n");  in swap_init_sysfs()
900 		pr_err("failed to register swap group\n");  in swap_init_sysfs()