linux/include/linux/mm_types.h
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   1#ifndef _LINUX_MM_TYPES_H
   2#define _LINUX_MM_TYPES_H
   3
   4#include <linux/auxvec.h>
   5#include <linux/types.h>
   6#include <linux/threads.h>
   7#include <linux/list.h>
   8#include <linux/spinlock.h>
   9#include <linux/prio_tree.h>
  10#include <linux/rbtree.h>
  11#include <linux/rwsem.h>
  12#include <linux/completion.h>
  13#include <linux/cpumask.h>
  14#include <asm/page.h>
  15#include <asm/mmu.h>
  16
  17#ifndef AT_VECTOR_SIZE_ARCH
  18#define AT_VECTOR_SIZE_ARCH 0
  19#endif
  20#define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1))
  21
  22struct address_space;
  23
  24#define USE_SPLIT_PTLOCKS       (NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS)
  25
  26#if USE_SPLIT_PTLOCKS
  27typedef atomic_long_t mm_counter_t;
  28#else  /* !USE_SPLIT_PTLOCKS */
  29typedef unsigned long mm_counter_t;
  30#endif /* !USE_SPLIT_PTLOCKS */
  31
  32/*
  33 * Each physical page in the system has a struct page associated with
  34 * it to keep track of whatever it is we are using the page for at the
  35 * moment. Note that we have no way to track which tasks are using
  36 * a page, though if it is a pagecache page, rmap structures can tell us
  37 * who is mapping it.
  38 */
  39struct page {
  40        unsigned long flags;            /* Atomic flags, some possibly
  41                                         * updated asynchronously */
  42        atomic_t _count;                /* Usage count, see below. */
  43        union {
  44                atomic_t _mapcount;     /* Count of ptes mapped in mms,
  45                                         * to show when page is mapped
  46                                         * & limit reverse map searches.
  47                                         */
  48                struct {                /* SLUB */
  49                        u16 inuse;
  50                        u16 objects;
  51                };
  52        };
  53        union {
  54            struct {
  55                unsigned long private;          /* Mapping-private opaque data:
  56                                                 * usually used for buffer_heads
  57                                                 * if PagePrivate set; used for
  58                                                 * swp_entry_t if PageSwapCache;
  59                                                 * indicates order in the buddy
  60                                                 * system if PG_buddy is set.
  61                                                 */
  62                struct address_space *mapping;  /* If low bit clear, points to
  63                                                 * inode address_space, or NULL.
  64                                                 * If page mapped as anonymous
  65                                                 * memory, low bit is set, and
  66                                                 * it points to anon_vma object:
  67                                                 * see PAGE_MAPPING_ANON below.
  68                                                 */
  69            };
  70#if USE_SPLIT_PTLOCKS
  71            spinlock_t ptl;
  72#endif
  73            struct kmem_cache *slab;    /* SLUB: Pointer to slab */
  74            struct page *first_page;    /* Compound tail pages */
  75        };
  76        union {
  77                pgoff_t index;          /* Our offset within mapping. */
  78                void *freelist;         /* SLUB: freelist req. slab lock */
  79        };
  80        struct list_head lru;           /* Pageout list, eg. active_list
  81                                         * protected by zone->lru_lock !
  82                                         */
  83        /*
  84         * On machines where all RAM is mapped into kernel address space,
  85         * we can simply calculate the virtual address. On machines with
  86         * highmem some memory is mapped into kernel virtual memory
  87         * dynamically, so we need a place to store that address.
  88         * Note that this field could be 16 bits on x86 ... ;)
  89         *
  90         * Architectures with slow multiplication can define
  91         * WANT_PAGE_VIRTUAL in asm/page.h
  92         */
  93#if defined(WANT_PAGE_VIRTUAL)
  94        void *virtual;                  /* Kernel virtual address (NULL if
  95                                           not kmapped, ie. highmem) */
  96#endif /* WANT_PAGE_VIRTUAL */
  97};
  98
  99/*
 100 * This struct defines a memory VMM memory area. There is one of these
 101 * per VM-area/task.  A VM area is any part of the process virtual memory
 102 * space that has a special rule for the page-fault handlers (ie a shared
 103 * library, the executable area etc).
 104 */
 105struct vm_area_struct {
 106        struct mm_struct * vm_mm;       /* The address space we belong to. */
 107        unsigned long vm_start;         /* Our start address within vm_mm. */
 108        unsigned long vm_end;           /* The first byte after our end address
 109                                           within vm_mm. */
 110
 111        /* linked list of VM areas per task, sorted by address */
 112        struct vm_area_struct *vm_next;
 113
 114        pgprot_t vm_page_prot;          /* Access permissions of this VMA. */
 115        unsigned long vm_flags;         /* Flags, see mm.h. */
 116
 117        struct rb_node vm_rb;
 118
 119        /*
 120         * For areas with an address space and backing store,
 121         * linkage into the address_space->i_mmap prio tree, or
 122         * linkage to the list of like vmas hanging off its node, or
 123         * linkage of vma in the address_space->i_mmap_nonlinear list.
 124         */
 125        union {
 126                struct {
 127                        struct list_head list;
 128                        void *parent;   /* aligns with prio_tree_node parent */
 129                        struct vm_area_struct *head;
 130                } vm_set;
 131
 132                struct raw_prio_tree_node prio_tree_node;
 133        } shared;
 134
 135        /*
 136         * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
 137         * list, after a COW of one of the file pages.  A MAP_SHARED vma
 138         * can only be in the i_mmap tree.  An anonymous MAP_PRIVATE, stack
 139         * or brk vma (with NULL file) can only be in an anon_vma list.
 140         */
 141        struct list_head anon_vma_node; /* Serialized by anon_vma->lock */
 142        struct anon_vma *anon_vma;      /* Serialized by page_table_lock */
 143
 144        /* Function pointers to deal with this struct. */
 145        struct vm_operations_struct * vm_ops;
 146
 147        /* Information about our backing store: */
 148        unsigned long vm_pgoff;         /* Offset (within vm_file) in PAGE_SIZE
 149                                           units, *not* PAGE_CACHE_SIZE */
 150        struct file * vm_file;          /* File we map to (can be NULL). */
 151        void * vm_private_data;         /* was vm_pte (shared mem) */
 152        unsigned long vm_truncate_count;/* truncate_count or restart_addr */
 153
 154#ifndef CONFIG_MMU
 155        atomic_t vm_usage;              /* refcount (VMAs shared if !MMU) */
 156#endif
 157#ifdef CONFIG_NUMA
 158        struct mempolicy *vm_policy;    /* NUMA policy for the VMA */
 159#endif
 160};
 161
 162struct core_thread {
 163        struct task_struct *task;
 164        struct core_thread *next;
 165};
 166
 167struct core_state {
 168        atomic_t nr_threads;
 169        struct core_thread dumper;
 170        struct completion startup;
 171};
 172
 173struct mm_struct {
 174        struct vm_area_struct * mmap;           /* list of VMAs */
 175        struct rb_root mm_rb;
 176        struct vm_area_struct * mmap_cache;     /* last find_vma result */
 177        unsigned long (*get_unmapped_area) (struct file *filp,
 178                                unsigned long addr, unsigned long len,
 179                                unsigned long pgoff, unsigned long flags);
 180        void (*unmap_area) (struct mm_struct *mm, unsigned long addr);
 181        unsigned long mmap_base;                /* base of mmap area */
 182        unsigned long task_size;                /* size of task vm space */
 183        unsigned long cached_hole_size;         /* if non-zero, the largest hole below free_area_cache */
 184        unsigned long free_area_cache;          /* first hole of size cached_hole_size or larger */
 185        pgd_t * pgd;
 186        atomic_t mm_users;                      /* How many users with user space? */
 187        atomic_t mm_count;                      /* How many references to "struct mm_struct" (users count as 1) */
 188        int map_count;                          /* number of VMAs */
 189        struct rw_semaphore mmap_sem;
 190        spinlock_t page_table_lock;             /* Protects page tables and some counters */
 191
 192        struct list_head mmlist;                /* List of maybe swapped mm's.  These are globally strung
 193                                                 * together off init_mm.mmlist, and are protected
 194                                                 * by mmlist_lock
 195                                                 */
 196
 197        /* Special counters, in some configurations protected by the
 198         * page_table_lock, in other configurations by being atomic.
 199         */
 200        mm_counter_t _file_rss;
 201        mm_counter_t _anon_rss;
 202
 203        unsigned long hiwater_rss;      /* High-watermark of RSS usage */
 204        unsigned long hiwater_vm;       /* High-water virtual memory usage */
 205
 206        unsigned long total_vm, locked_vm, shared_vm, exec_vm;
 207        unsigned long stack_vm, reserved_vm, def_flags, nr_ptes;
 208        unsigned long start_code, end_code, start_data, end_data;
 209        unsigned long start_brk, brk, start_stack;
 210        unsigned long arg_start, arg_end, env_start, env_end;
 211
 212        unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
 213
 214        cpumask_t cpu_vm_mask;
 215
 216        /* Architecture-specific MM context */
 217        mm_context_t context;
 218
 219        /* Swap token stuff */
 220        /*
 221         * Last value of global fault stamp as seen by this process.
 222         * In other words, this value gives an indication of how long
 223         * it has been since this task got the token.
 224         * Look at mm/thrash.c
 225         */
 226        unsigned int faultstamp;
 227        unsigned int token_priority;
 228        unsigned int last_interval;
 229
 230        unsigned long flags; /* Must use atomic bitops to access the bits */
 231
 232        struct core_state *core_state; /* coredumping support */
 233
 234        /* aio bits */
 235        rwlock_t                ioctx_list_lock;        /* aio lock */
 236        struct kioctx           *ioctx_list;
 237#ifdef CONFIG_MM_OWNER
 238        /*
 239         * "owner" points to a task that is regarded as the canonical
 240         * user/owner of this mm. All of the following must be true in
 241         * order for it to be changed:
 242         *
 243         * current == mm->owner
 244         * current->mm != mm
 245         * new_owner->mm == mm
 246         * new_owner->alloc_lock is held
 247         */
 248        struct task_struct *owner;
 249#endif
 250
 251#ifdef CONFIG_PROC_FS
 252        /* store ref to file /proc/<pid>/exe symlink points to */
 253        struct file *exe_file;
 254        unsigned long num_exe_file_vmas;
 255#endif
 256#ifdef CONFIG_MMU_NOTIFIER
 257        struct mmu_notifier_mm *mmu_notifier_mm;
 258#endif
 259};
 260
 261#endif /* _LINUX_MM_TYPES_H */
 262
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