502 lines
14 KiB
C
502 lines
14 KiB
C
#ifndef _LINUX_SWAP_H
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#define _LINUX_SWAP_H
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#include <linux/spinlock.h>
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#include <linux/linkage.h>
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#include <linux/mmzone.h>
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#include <linux/list.h>
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#include <linux/memcontrol.h>
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#include <linux/sched.h>
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#include <linux/node.h>
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#include <asm/atomic.h>
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#include <asm/page.h>
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struct notifier_block;
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struct bio;
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#define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */
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#define SWAP_FLAG_PRIO_MASK 0x7fff
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#define SWAP_FLAG_PRIO_SHIFT 0
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static inline int current_is_kswapd(void)
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{
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return current->flags & PF_KSWAPD;
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}
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/*
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* MAX_SWAPFILES defines the maximum number of swaptypes: things which can
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* be swapped to. The swap type and the offset into that swap type are
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* encoded into pte's and into pgoff_t's in the swapcache. Using five bits
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* for the type means that the maximum number of swapcache pages is 27 bits
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* on 32-bit-pgoff_t architectures. And that assumes that the architecture packs
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* the type/offset into the pte as 5/27 as well.
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*/
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#define MAX_SWAPFILES_SHIFT 5
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/*
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* Use some of the swap files numbers for other purposes. This
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* is a convenient way to hook into the VM to trigger special
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* actions on faults.
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*/
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/*
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* NUMA node memory migration support
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*/
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#ifdef CONFIG_MIGRATION
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#define SWP_MIGRATION_NUM 2
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#define SWP_MIGRATION_READ (MAX_SWAPFILES + SWP_HWPOISON_NUM)
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#define SWP_MIGRATION_WRITE (MAX_SWAPFILES + SWP_HWPOISON_NUM + 1)
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#else
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#define SWP_MIGRATION_NUM 0
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#endif
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/*
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* Handling of hardware poisoned pages with memory corruption.
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*/
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#ifdef CONFIG_MEMORY_FAILURE
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#define SWP_HWPOISON_NUM 1
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#define SWP_HWPOISON MAX_SWAPFILES
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#else
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#define SWP_HWPOISON_NUM 0
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#endif
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#define MAX_SWAPFILES \
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((1 << MAX_SWAPFILES_SHIFT) - SWP_MIGRATION_NUM - SWP_HWPOISON_NUM)
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/*
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* Magic header for a swap area. The first part of the union is
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* what the swap magic looks like for the old (limited to 128MB)
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* swap area format, the second part of the union adds - in the
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* old reserved area - some extra information. Note that the first
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* kilobyte is reserved for boot loader or disk label stuff...
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*
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* Having the magic at the end of the PAGE_SIZE makes detecting swap
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* areas somewhat tricky on machines that support multiple page sizes.
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* For 2.5 we'll probably want to move the magic to just beyond the
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* bootbits...
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*/
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union swap_header {
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struct {
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char reserved[PAGE_SIZE - 10];
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char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */
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} magic;
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struct {
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char bootbits[1024]; /* Space for disklabel etc. */
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__u32 version;
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__u32 last_page;
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__u32 nr_badpages;
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unsigned char sws_uuid[16];
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unsigned char sws_volume[16];
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__u32 padding[117];
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__u32 badpages[1];
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} info;
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};
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/* A swap entry has to fit into a "unsigned long", as
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* the entry is hidden in the "index" field of the
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* swapper address space.
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*/
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typedef struct {
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unsigned long val;
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} swp_entry_t;
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/*
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* current->reclaim_state points to one of these when a task is running
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* memory reclaim
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*/
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struct reclaim_state {
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unsigned long reclaimed_slab;
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};
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#ifdef __KERNEL__
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struct address_space;
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struct sysinfo;
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struct writeback_control;
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struct zone;
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/*
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* A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of
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* disk blocks. A list of swap extents maps the entire swapfile. (Where the
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* term `swapfile' refers to either a blockdevice or an IS_REG file. Apart
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* from setup, they're handled identically.
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*
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* We always assume that blocks are of size PAGE_SIZE.
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*/
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struct swap_extent {
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struct list_head list;
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pgoff_t start_page;
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pgoff_t nr_pages;
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sector_t start_block;
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};
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/*
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* Max bad pages in the new format..
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*/
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#define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x)
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#define MAX_SWAP_BADPAGES \
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((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int))
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enum {
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SWP_USED = (1 << 0), /* is slot in swap_info[] used? */
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SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */
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SWP_DISCARDABLE = (1 << 2), /* blkdev supports discard */
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SWP_DISCARDING = (1 << 3), /* now discarding a free cluster */
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SWP_SOLIDSTATE = (1 << 4), /* blkdev seeks are cheap */
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SWP_CONTINUED = (1 << 5), /* swap_map has count continuation */
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SWP_BLKDEV = (1 << 6), /* its a block device */
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/* add others here before... */
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SWP_SCANNING = (1 << 8), /* refcount in scan_swap_map */
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};
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#define SWAP_CLUSTER_MAX 32
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#define COMPACT_CLUSTER_MAX SWAP_CLUSTER_MAX
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#define SWAP_MAP_MAX 0x3e /* Max duplication count, in first swap_map */
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#define SWAP_MAP_BAD 0x3f /* Note pageblock is bad, in first swap_map */
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#define SWAP_HAS_CACHE 0x40 /* Flag page is cached, in first swap_map */
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#define SWAP_CONT_MAX 0x7f /* Max count, in each swap_map continuation */
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#define COUNT_CONTINUED 0x80 /* See swap_map continuation for full count */
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#define SWAP_MAP_SHMEM 0xbf /* Owned by shmem/tmpfs, in first swap_map */
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/*
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* The in-memory structure used to track swap areas.
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*/
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struct swap_info_struct {
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unsigned long flags; /* SWP_USED etc: see above */
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signed short prio; /* swap priority of this type */
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signed char type; /* strange name for an index */
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signed char next; /* next type on the swap list */
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unsigned int max; /* extent of the swap_map */
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unsigned char *swap_map; /* vmalloc'ed array of usage counts */
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unsigned int lowest_bit; /* index of first free in swap_map */
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unsigned int highest_bit; /* index of last free in swap_map */
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unsigned int pages; /* total of usable pages of swap */
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unsigned int inuse_pages; /* number of those currently in use */
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unsigned int cluster_next; /* likely index for next allocation */
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unsigned int cluster_nr; /* countdown to next cluster search */
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unsigned int lowest_alloc; /* while preparing discard cluster */
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unsigned int highest_alloc; /* while preparing discard cluster */
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struct swap_extent *curr_swap_extent;
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struct swap_extent first_swap_extent;
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struct block_device *bdev; /* swap device or bdev of swap file */
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struct file *swap_file; /* seldom referenced */
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unsigned int old_block_size; /* seldom referenced */
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};
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struct swap_list_t {
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int head; /* head of priority-ordered swapfile list */
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int next; /* swapfile to be used next */
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};
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/* Swap 50% full? Release swapcache more aggressively.. */
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#define vm_swap_full() (nr_swap_pages*2 < total_swap_pages)
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/* linux/mm/page_alloc.c */
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extern unsigned long totalram_pages;
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extern unsigned long totalreserve_pages;
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extern unsigned int nr_free_buffer_pages(void);
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extern unsigned int nr_free_pagecache_pages(void);
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/* Definition of global_page_state not available yet */
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#define nr_free_pages() global_page_state(NR_FREE_PAGES)
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/* linux/mm/swap.c */
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extern void __lru_cache_add(struct page *, enum lru_list lru);
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extern void lru_cache_add_lru(struct page *, enum lru_list lru);
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extern void activate_page(struct page *);
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extern void mark_page_accessed(struct page *);
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extern void lru_add_drain(void);
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extern int lru_add_drain_all(void);
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extern void rotate_reclaimable_page(struct page *page);
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extern void swap_setup(void);
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extern void add_page_to_unevictable_list(struct page *page);
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/**
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* lru_cache_add: add a page to the page lists
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* @page: the page to add
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*/
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static inline void lru_cache_add_anon(struct page *page)
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{
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__lru_cache_add(page, LRU_INACTIVE_ANON);
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}
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static inline void lru_cache_add_file(struct page *page)
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{
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__lru_cache_add(page, LRU_INACTIVE_FILE);
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}
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/* LRU Isolation modes. */
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#define ISOLATE_INACTIVE 0 /* Isolate inactive pages. */
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#define ISOLATE_ACTIVE 1 /* Isolate active pages. */
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#define ISOLATE_BOTH 2 /* Isolate both active and inactive pages. */
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/* linux/mm/vmscan.c */
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extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
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gfp_t gfp_mask, nodemask_t *mask);
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extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem,
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gfp_t gfp_mask, bool noswap,
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unsigned int swappiness);
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extern unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem,
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gfp_t gfp_mask, bool noswap,
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unsigned int swappiness,
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struct zone *zone,
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int nid);
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extern int __isolate_lru_page(struct page *page, int mode, int file);
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extern unsigned long shrink_all_memory(unsigned long nr_pages);
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extern int vm_swappiness;
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extern int remove_mapping(struct address_space *mapping, struct page *page);
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extern long vm_total_pages;
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#ifdef CONFIG_NUMA
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extern int zone_reclaim_mode;
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extern int sysctl_min_unmapped_ratio;
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extern int sysctl_min_slab_ratio;
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extern int zone_reclaim(struct zone *, gfp_t, unsigned int);
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#else
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#define zone_reclaim_mode 0
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static inline int zone_reclaim(struct zone *z, gfp_t mask, unsigned int order)
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{
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return 0;
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}
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#endif
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extern int page_evictable(struct page *page, struct vm_area_struct *vma);
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extern void scan_mapping_unevictable_pages(struct address_space *);
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extern unsigned long scan_unevictable_pages;
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extern int scan_unevictable_handler(struct ctl_table *, int,
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void __user *, size_t *, loff_t *);
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extern int scan_unevictable_register_node(struct node *node);
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extern void scan_unevictable_unregister_node(struct node *node);
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extern int kswapd_run(int nid);
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extern void kswapd_stop(int nid);
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#ifdef CONFIG_MMU
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/* linux/mm/shmem.c */
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extern int shmem_unuse(swp_entry_t entry, struct page *page);
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#endif /* CONFIG_MMU */
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#ifdef CONFIG_CGROUP_MEM_RES_CTLR
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extern void mem_cgroup_get_shmem_target(struct inode *inode, pgoff_t pgoff,
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struct page **pagep, swp_entry_t *ent);
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#endif
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extern void swap_unplug_io_fn(struct backing_dev_info *, struct page *);
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#ifdef CONFIG_SWAP
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/* linux/mm/page_io.c */
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extern int swap_readpage(struct page *);
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extern int swap_writepage(struct page *page, struct writeback_control *wbc);
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extern void end_swap_bio_read(struct bio *bio, int err);
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/* linux/mm/swap_state.c */
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extern struct address_space swapper_space;
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#define total_swapcache_pages swapper_space.nrpages
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extern void show_swap_cache_info(void);
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extern int add_to_swap(struct page *);
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extern int add_to_swap_cache(struct page *, swp_entry_t, gfp_t);
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extern void __delete_from_swap_cache(struct page *);
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extern void delete_from_swap_cache(struct page *);
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extern void free_page_and_swap_cache(struct page *);
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extern void free_pages_and_swap_cache(struct page **, int);
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extern struct page *lookup_swap_cache(swp_entry_t);
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extern struct page *read_swap_cache_async(swp_entry_t, gfp_t,
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struct vm_area_struct *vma, unsigned long addr);
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extern struct page *swapin_readahead(swp_entry_t, gfp_t,
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struct vm_area_struct *vma, unsigned long addr);
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/* linux/mm/swapfile.c */
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extern long nr_swap_pages;
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extern long total_swap_pages;
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extern void si_swapinfo(struct sysinfo *);
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extern swp_entry_t get_swap_page(void);
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extern swp_entry_t get_swap_page_of_type(int);
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extern int valid_swaphandles(swp_entry_t, unsigned long *);
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extern int add_swap_count_continuation(swp_entry_t, gfp_t);
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extern void swap_shmem_alloc(swp_entry_t);
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extern int swap_duplicate(swp_entry_t);
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extern int swapcache_prepare(swp_entry_t);
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extern void swap_free(swp_entry_t);
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extern void swapcache_free(swp_entry_t, struct page *page);
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extern int free_swap_and_cache(swp_entry_t);
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extern int swap_type_of(dev_t, sector_t, struct block_device **);
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extern unsigned int count_swap_pages(int, int);
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extern sector_t map_swap_page(struct page *, struct block_device **);
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extern sector_t swapdev_block(int, pgoff_t);
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extern int reuse_swap_page(struct page *);
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extern int try_to_free_swap(struct page *);
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struct backing_dev_info;
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/* linux/mm/thrash.c */
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extern struct mm_struct *swap_token_mm;
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extern void grab_swap_token(struct mm_struct *);
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extern void __put_swap_token(struct mm_struct *);
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static inline int has_swap_token(struct mm_struct *mm)
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{
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return (mm == swap_token_mm);
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}
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static inline void put_swap_token(struct mm_struct *mm)
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{
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if (has_swap_token(mm))
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__put_swap_token(mm);
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}
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static inline void disable_swap_token(void)
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{
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put_swap_token(swap_token_mm);
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}
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#ifdef CONFIG_CGROUP_MEM_RES_CTLR
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extern void
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mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout);
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extern int mem_cgroup_count_swap_user(swp_entry_t ent, struct page **pagep);
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#else
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static inline void
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mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
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{
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}
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#endif
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#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
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extern void mem_cgroup_uncharge_swap(swp_entry_t ent);
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#else
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static inline void mem_cgroup_uncharge_swap(swp_entry_t ent)
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{
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}
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#endif
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#else /* CONFIG_SWAP */
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#define nr_swap_pages 0L
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#define total_swap_pages 0L
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#define total_swapcache_pages 0UL
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#define si_swapinfo(val) \
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do { (val)->freeswap = (val)->totalswap = 0; } while (0)
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/* only sparc can not include linux/pagemap.h in this file
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* so leave page_cache_release and release_pages undeclared... */
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#define free_page_and_swap_cache(page) \
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page_cache_release(page)
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#define free_pages_and_swap_cache(pages, nr) \
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release_pages((pages), (nr), 0);
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static inline void show_swap_cache_info(void)
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{
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}
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#define free_swap_and_cache(swp) is_migration_entry(swp)
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#define swapcache_prepare(swp) is_migration_entry(swp)
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static inline int add_swap_count_continuation(swp_entry_t swp, gfp_t gfp_mask)
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{
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return 0;
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}
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static inline void swap_shmem_alloc(swp_entry_t swp)
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{
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}
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static inline int swap_duplicate(swp_entry_t swp)
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{
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return 0;
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}
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static inline void swap_free(swp_entry_t swp)
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{
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}
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static inline void swapcache_free(swp_entry_t swp, struct page *page)
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{
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}
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static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
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struct vm_area_struct *vma, unsigned long addr)
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{
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return NULL;
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}
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static inline int swap_writepage(struct page *p, struct writeback_control *wbc)
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{
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return 0;
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}
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static inline struct page *lookup_swap_cache(swp_entry_t swp)
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{
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return NULL;
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}
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static inline int add_to_swap(struct page *page)
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{
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return 0;
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}
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static inline int add_to_swap_cache(struct page *page, swp_entry_t entry,
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gfp_t gfp_mask)
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{
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return -1;
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}
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static inline void __delete_from_swap_cache(struct page *page)
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{
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}
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static inline void delete_from_swap_cache(struct page *page)
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{
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}
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#define reuse_swap_page(page) (page_mapcount(page) == 1)
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static inline int try_to_free_swap(struct page *page)
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{
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return 0;
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}
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static inline swp_entry_t get_swap_page(void)
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{
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swp_entry_t entry;
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entry.val = 0;
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return entry;
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}
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/* linux/mm/thrash.c */
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static inline void put_swap_token(struct mm_struct *mm)
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{
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}
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static inline void grab_swap_token(struct mm_struct *mm)
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{
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}
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static inline int has_swap_token(struct mm_struct *mm)
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{
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return 0;
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}
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static inline void disable_swap_token(void)
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{
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}
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static inline void
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mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent)
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{
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}
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#ifdef CONFIG_CGROUP_MEM_RES_CTLR
|
|
static inline int
|
|
mem_cgroup_count_swap_user(swp_entry_t ent, struct page **pagep)
|
|
{
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|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#endif /* CONFIG_SWAP */
|
|
#endif /* __KERNEL__*/
|
|
#endif /* _LINUX_SWAP_H */
|