1 #ifndef _LINUX_MM_TYPES_H
2 #define _LINUX_MM_TYPES_H
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 <linux/page-debug-flags.h>
15 #include <linux/uprobes.h>
19 #ifndef AT_VECTOR_SIZE_ARCH
20 #define AT_VECTOR_SIZE_ARCH 0
22 #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1))
26 #define USE_SPLIT_PTLOCKS (NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS)
29 * Each physical page in the system has a struct page associated with
30 * it to keep track of whatever it is we are using the page for at the
31 * moment. Note that we have no way to track which tasks are using
32 * a page, though if it is a pagecache page, rmap structures can tell us
35 * The objects in struct page are organized in double word blocks in
36 * order to allows us to use atomic double word operations on portions
37 * of struct page. That is currently only used by slub but the arrangement
38 * allows the use of atomic double word operations on the flags/mapping
39 * and lru list pointers also.
42 /* First double word block */
43 unsigned long flags
; /* Atomic flags, some possibly
44 * updated asynchronously */
45 struct address_space
*mapping
; /* If low bit clear, points to
46 * inode address_space, or NULL.
47 * If page mapped as anonymous
48 * memory, low bit is set, and
49 * it points to anon_vma object:
50 * see PAGE_MAPPING_ANON below.
52 /* Second double word */
55 pgoff_t index
; /* Our offset within mapping. */
56 void *freelist
; /* slub first free object */
60 /* Used for cmpxchg_double in slub */
61 unsigned long counters
;
67 * Count of ptes mapped in
68 * mms, to show when page is
69 * mapped & limit reverse map
72 * Used also for tail pages
73 * refcounting instead of
74 * _count. Tail pages cannot
75 * be mapped and keeping the
76 * tail page _count zero at
77 * all times guarantees
78 * get_page_unless_zero() will
79 * never succeed on tail
90 atomic_t _count
; /* Usage count, see below. */
95 /* Third double word block */
97 struct list_head lru
; /* Pageout list, eg. active_list
98 * protected by zone->lru_lock !
100 struct { /* slub per cpu partial pages */
101 struct page
*next
; /* Next partial slab */
103 int pages
; /* Nr of partial slabs left */
104 int pobjects
; /* Approximate # of objects */
112 /* Remainder is not double word aligned */
114 unsigned long private; /* Mapping-private opaque data:
115 * usually used for buffer_heads
116 * if PagePrivate set; used for
117 * swp_entry_t if PageSwapCache;
118 * indicates order in the buddy
119 * system if PG_buddy is set.
121 #if USE_SPLIT_PTLOCKS
124 struct kmem_cache
*slab
; /* SLUB: Pointer to slab */
125 struct page
*first_page
; /* Compound tail pages */
129 * On machines where all RAM is mapped into kernel address space,
130 * we can simply calculate the virtual address. On machines with
131 * highmem some memory is mapped into kernel virtual memory
132 * dynamically, so we need a place to store that address.
133 * Note that this field could be 16 bits on x86 ... ;)
135 * Architectures with slow multiplication can define
136 * WANT_PAGE_VIRTUAL in asm/page.h
138 #if defined(WANT_PAGE_VIRTUAL)
139 void *virtual; /* Kernel virtual address (NULL if
140 not kmapped, ie. highmem) */
141 #endif /* WANT_PAGE_VIRTUAL */
142 #ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
143 unsigned long debug_flags
; /* Use atomic bitops on this */
146 #ifdef CONFIG_KMEMCHECK
148 * kmemcheck wants to track the status of each byte in a page; this
149 * is a pointer to such a status block. NULL if not tracked.
155 * The struct page can be forced to be double word aligned so that atomic ops
156 * on double words work. The SLUB allocator can make use of such a feature.
158 #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE
159 __aligned(2 * sizeof(unsigned long))
165 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
174 typedef unsigned long __nocast vm_flags_t
;
177 * A region containing a mapping of a non-memory backed file under NOMMU
178 * conditions. These are held in a global tree and are pinned by the VMAs that
182 struct rb_node vm_rb
; /* link in global region tree */
183 vm_flags_t vm_flags
; /* VMA vm_flags */
184 unsigned long vm_start
; /* start address of region */
185 unsigned long vm_end
; /* region initialised to here */
186 unsigned long vm_top
; /* region allocated to here */
187 unsigned long vm_pgoff
; /* the offset in vm_file corresponding to vm_start */
188 struct file
*vm_file
; /* the backing file or NULL */
190 int vm_usage
; /* region usage count (access under nommu_region_sem) */
191 bool vm_icache_flushed
: 1; /* true if the icache has been flushed for
196 * This struct defines a memory VMM memory area. There is one of these
197 * per VM-area/task. A VM area is any part of the process virtual memory
198 * space that has a special rule for the page-fault handlers (ie a shared
199 * library, the executable area etc).
201 struct vm_area_struct
{
202 struct mm_struct
* vm_mm
; /* The address space we belong to. */
203 unsigned long vm_start
; /* Our start address within vm_mm. */
204 unsigned long vm_end
; /* The first byte after our end address
207 /* linked list of VM areas per task, sorted by address */
208 struct vm_area_struct
*vm_next
, *vm_prev
;
210 pgprot_t vm_page_prot
; /* Access permissions of this VMA. */
211 unsigned long vm_flags
; /* Flags, see mm.h. */
213 struct rb_node vm_rb
;
216 * For areas with an address space and backing store,
217 * linkage into the address_space->i_mmap prio tree, or
218 * linkage to the list of like vmas hanging off its node, or
219 * linkage of vma in the address_space->i_mmap_nonlinear list.
223 struct list_head list
;
224 void *parent
; /* aligns with prio_tree_node parent */
225 struct vm_area_struct
*head
;
228 struct raw_prio_tree_node prio_tree_node
;
232 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
233 * list, after a COW of one of the file pages. A MAP_SHARED vma
234 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack
235 * or brk vma (with NULL file) can only be in an anon_vma list.
237 struct list_head anon_vma_chain
; /* Serialized by mmap_sem &
239 struct anon_vma
*anon_vma
; /* Serialized by page_table_lock */
241 /* Function pointers to deal with this struct. */
242 const struct vm_operations_struct
*vm_ops
;
244 /* Information about our backing store: */
245 unsigned long vm_pgoff
; /* Offset (within vm_file) in PAGE_SIZE
246 units, *not* PAGE_CACHE_SIZE */
247 struct file
* vm_file
; /* File we map to (can be NULL). */
248 void * vm_private_data
; /* was vm_pte (shared mem) */
251 struct vm_region
*vm_region
; /* NOMMU mapping region */
254 struct mempolicy
*vm_policy
; /* NUMA policy for the VMA */
259 struct task_struct
*task
;
260 struct core_thread
*next
;
265 struct core_thread dumper
;
266 struct completion startup
;
276 #if USE_SPLIT_PTLOCKS && defined(CONFIG_MMU)
277 #define SPLIT_RSS_COUNTING
278 /* per-thread cached information, */
279 struct task_rss_stat
{
280 int events
; /* for synchronization threshold */
281 int count
[NR_MM_COUNTERS
];
283 #endif /* USE_SPLIT_PTLOCKS */
286 atomic_long_t count
[NR_MM_COUNTERS
];
290 struct vm_area_struct
* mmap
; /* list of VMAs */
291 struct rb_root mm_rb
;
292 struct vm_area_struct
* mmap_cache
; /* last find_vma result */
294 unsigned long (*get_unmapped_area
) (struct file
*filp
,
295 unsigned long addr
, unsigned long len
,
296 unsigned long pgoff
, unsigned long flags
);
297 void (*unmap_area
) (struct mm_struct
*mm
, unsigned long addr
);
299 unsigned long mmap_base
; /* base of mmap area */
300 unsigned long task_size
; /* size of task vm space */
301 unsigned long cached_hole_size
; /* if non-zero, the largest hole below free_area_cache */
302 unsigned long free_area_cache
; /* first hole of size cached_hole_size or larger */
304 atomic_t mm_users
; /* How many users with user space? */
305 atomic_t mm_count
; /* How many references to "struct mm_struct" (users count as 1) */
306 int map_count
; /* number of VMAs */
308 spinlock_t page_table_lock
; /* Protects page tables and some counters */
309 struct rw_semaphore mmap_sem
;
311 struct list_head mmlist
; /* List of maybe swapped mm's. These are globally strung
312 * together off init_mm.mmlist, and are protected
317 unsigned long hiwater_rss
; /* High-watermark of RSS usage */
318 unsigned long hiwater_vm
; /* High-water virtual memory usage */
320 unsigned long total_vm
; /* Total pages mapped */
321 unsigned long locked_vm
; /* Pages that have PG_mlocked set */
322 unsigned long pinned_vm
; /* Refcount permanently increased */
323 unsigned long shared_vm
; /* Shared pages (files) */
324 unsigned long exec_vm
; /* VM_EXEC & ~VM_WRITE */
325 unsigned long stack_vm
; /* VM_GROWSUP/DOWN */
326 unsigned long reserved_vm
; /* VM_RESERVED|VM_IO pages */
327 unsigned long def_flags
;
328 unsigned long nr_ptes
; /* Page table pages */
329 unsigned long start_code
, end_code
, start_data
, end_data
;
330 unsigned long start_brk
, brk
, start_stack
;
331 unsigned long arg_start
, arg_end
, env_start
, env_end
;
333 unsigned long saved_auxv
[AT_VECTOR_SIZE
]; /* for /proc/PID/auxv */
336 * Special counters, in some configurations protected by the
337 * page_table_lock, in other configurations by being atomic.
339 struct mm_rss_stat rss_stat
;
341 struct linux_binfmt
*binfmt
;
343 cpumask_var_t cpu_vm_mask_var
;
345 /* Architecture-specific MM context */
346 mm_context_t context
;
348 unsigned long flags
; /* Must use atomic bitops to access the bits */
350 struct core_state
*core_state
; /* coredumping support */
352 spinlock_t ioctx_lock
;
353 struct hlist_head ioctx_list
;
355 #ifdef CONFIG_MM_OWNER
357 * "owner" points to a task that is regarded as the canonical
358 * user/owner of this mm. All of the following must be true in
359 * order for it to be changed:
361 * current == mm->owner
363 * new_owner->mm == mm
364 * new_owner->alloc_lock is held
366 struct task_struct __rcu
*owner
;
369 /* store ref to file /proc/<pid>/exe symlink points to */
370 struct file
*exe_file
;
371 unsigned long num_exe_file_vmas
;
372 #ifdef CONFIG_MMU_NOTIFIER
373 struct mmu_notifier_mm
*mmu_notifier_mm
;
375 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
376 pgtable_t pmd_huge_pte
; /* protected by page_table_lock */
378 #ifdef CONFIG_CPUMASK_OFFSTACK
379 struct cpumask cpumask_allocation
;
381 struct uprobes_state uprobes_state
;
384 static inline void mm_init_cpumask(struct mm_struct
*mm
)
386 #ifdef CONFIG_CPUMASK_OFFSTACK
387 mm
->cpu_vm_mask_var
= &mm
->cpumask_allocation
;
391 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */
392 static inline cpumask_t
*mm_cpumask(struct mm_struct
*mm
)
394 return mm
->cpu_vm_mask_var
;
397 #endif /* _LINUX_MM_TYPES_H */