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/rbtree.h>
10 #include <linux/rwsem.h>
11 #include <linux/completion.h>
12 #include <linux/cpumask.h>
13 #include <linux/page-debug-flags.h>
14 #include <linux/uprobes.h>
15 #include <linux/page-flags-layout.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/slob first free object */
57 bool pfmemalloc
; /* If set by the page allocator,
58 * ALLOC_NO_WATERMARKS was set
59 * and the low watermark was not
60 * met implying that the system
61 * is under some pressure. The
62 * caller should try ensure
63 * this page is only used to
69 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
70 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
71 /* Used for cmpxchg_double in slub */
72 unsigned long counters
;
75 * Keep _count separate from slub cmpxchg_double data.
76 * As the rest of the double word is protected by
77 * slab_lock but _count is not.
86 * Count of ptes mapped in
87 * mms, to show when page is
88 * mapped & limit reverse map
91 * Used also for tail pages
92 * refcounting instead of
93 * _count. Tail pages cannot
94 * be mapped and keeping the
95 * tail page _count zero at
96 * all times guarantees
97 * get_page_unless_zero() will
98 * never succeed on tail
108 int units
; /* SLOB */
110 atomic_t _count
; /* Usage count, see below. */
115 /* Third double word block */
117 struct list_head lru
; /* Pageout list, eg. active_list
118 * protected by zone->lru_lock !
120 struct { /* slub per cpu partial pages */
121 struct page
*next
; /* Next partial slab */
123 int pages
; /* Nr of partial slabs left */
124 int pobjects
; /* Approximate # of objects */
131 struct list_head list
; /* slobs list of pages */
132 struct slab
*slab_page
; /* slab fields */
135 /* Remainder is not double word aligned */
137 unsigned long private; /* Mapping-private opaque data:
138 * usually used for buffer_heads
139 * if PagePrivate set; used for
140 * swp_entry_t if PageSwapCache;
141 * indicates order in the buddy
142 * system if PG_buddy is set.
144 #if USE_SPLIT_PTLOCKS
147 struct kmem_cache
*slab_cache
; /* SL[AU]B: Pointer to slab */
148 struct page
*first_page
; /* Compound tail pages */
152 * On machines where all RAM is mapped into kernel address space,
153 * we can simply calculate the virtual address. On machines with
154 * highmem some memory is mapped into kernel virtual memory
155 * dynamically, so we need a place to store that address.
156 * Note that this field could be 16 bits on x86 ... ;)
158 * Architectures with slow multiplication can define
159 * WANT_PAGE_VIRTUAL in asm/page.h
161 #if defined(WANT_PAGE_VIRTUAL)
162 void *virtual; /* Kernel virtual address (NULL if
163 not kmapped, ie. highmem) */
164 #endif /* WANT_PAGE_VIRTUAL */
165 #ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
166 unsigned long debug_flags
; /* Use atomic bitops on this */
169 #ifdef CONFIG_KMEMCHECK
171 * kmemcheck wants to track the status of each byte in a page; this
172 * is a pointer to such a status block. NULL if not tracked.
177 #ifdef LAST_NID_NOT_IN_PAGE_FLAGS
182 * The struct page can be forced to be double word aligned so that atomic ops
183 * on double words work. The SLUB allocator can make use of such a feature.
185 #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE
186 __aligned(2 * sizeof(unsigned long))
192 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
201 typedef unsigned long __nocast vm_flags_t
;
204 * A region containing a mapping of a non-memory backed file under NOMMU
205 * conditions. These are held in a global tree and are pinned by the VMAs that
209 struct rb_node vm_rb
; /* link in global region tree */
210 vm_flags_t vm_flags
; /* VMA vm_flags */
211 unsigned long vm_start
; /* start address of region */
212 unsigned long vm_end
; /* region initialised to here */
213 unsigned long vm_top
; /* region allocated to here */
214 unsigned long vm_pgoff
; /* the offset in vm_file corresponding to vm_start */
215 struct file
*vm_file
; /* the backing file or NULL */
217 int vm_usage
; /* region usage count (access under nommu_region_sem) */
218 bool vm_icache_flushed
: 1; /* true if the icache has been flushed for
223 * This struct defines a memory VMM memory area. There is one of these
224 * per VM-area/task. A VM area is any part of the process virtual memory
225 * space that has a special rule for the page-fault handlers (ie a shared
226 * library, the executable area etc).
228 struct vm_area_struct
{
229 /* The first cache line has the info for VMA tree walking. */
231 unsigned long vm_start
; /* Our start address within vm_mm. */
232 unsigned long vm_end
; /* The first byte after our end address
235 /* linked list of VM areas per task, sorted by address */
236 struct vm_area_struct
*vm_next
, *vm_prev
;
238 struct rb_node vm_rb
;
241 * Largest free memory gap in bytes to the left of this VMA.
242 * Either between this VMA and vma->vm_prev, or between one of the
243 * VMAs below us in the VMA rbtree and its ->vm_prev. This helps
244 * get_unmapped_area find a free area of the right size.
246 unsigned long rb_subtree_gap
;
248 /* Second cache line starts here. */
250 struct mm_struct
*vm_mm
; /* The address space we belong to. */
251 pgprot_t vm_page_prot
; /* Access permissions of this VMA. */
252 unsigned long vm_flags
; /* Flags, see mm.h. */
255 * For areas with an address space and backing store,
256 * linkage into the address_space->i_mmap interval tree, or
257 * linkage of vma in the address_space->i_mmap_nonlinear list.
262 unsigned long rb_subtree_last
;
264 struct list_head nonlinear
;
268 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
269 * list, after a COW of one of the file pages. A MAP_SHARED vma
270 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack
271 * or brk vma (with NULL file) can only be in an anon_vma list.
273 struct list_head anon_vma_chain
; /* Serialized by mmap_sem &
275 struct anon_vma
*anon_vma
; /* Serialized by page_table_lock */
277 /* Function pointers to deal with this struct. */
278 const struct vm_operations_struct
*vm_ops
;
280 /* Information about our backing store: */
281 unsigned long vm_pgoff
; /* Offset (within vm_file) in PAGE_SIZE
282 units, *not* PAGE_CACHE_SIZE */
283 struct file
* vm_file
; /* File we map to (can be NULL). */
284 void * vm_private_data
; /* was vm_pte (shared mem) */
287 struct vm_region
*vm_region
; /* NOMMU mapping region */
290 struct mempolicy
*vm_policy
; /* NUMA policy for the VMA */
295 struct task_struct
*task
;
296 struct core_thread
*next
;
301 struct core_thread dumper
;
302 struct completion startup
;
312 #if USE_SPLIT_PTLOCKS && defined(CONFIG_MMU)
313 #define SPLIT_RSS_COUNTING
314 /* per-thread cached information, */
315 struct task_rss_stat
{
316 int events
; /* for synchronization threshold */
317 int count
[NR_MM_COUNTERS
];
319 #endif /* USE_SPLIT_PTLOCKS */
322 atomic_long_t count
[NR_MM_COUNTERS
];
327 struct vm_area_struct
* mmap
; /* list of VMAs */
328 struct rb_root mm_rb
;
329 struct vm_area_struct
* mmap_cache
; /* last find_vma result */
331 unsigned long (*get_unmapped_area
) (struct file
*filp
,
332 unsigned long addr
, unsigned long len
,
333 unsigned long pgoff
, unsigned long flags
);
335 unsigned long mmap_base
; /* base of mmap area */
336 unsigned long task_size
; /* size of task vm space */
337 unsigned long highest_vm_end
; /* highest vma end address */
339 atomic_t mm_users
; /* How many users with user space? */
340 atomic_t mm_count
; /* How many references to "struct mm_struct" (users count as 1) */
341 int map_count
; /* number of VMAs */
343 spinlock_t page_table_lock
; /* Protects page tables and some counters */
344 struct rw_semaphore mmap_sem
;
346 struct list_head mmlist
; /* List of maybe swapped mm's. These are globally strung
347 * together off init_mm.mmlist, and are protected
352 unsigned long hiwater_rss
; /* High-watermark of RSS usage */
353 unsigned long hiwater_vm
; /* High-water virtual memory usage */
355 unsigned long total_vm
; /* Total pages mapped */
356 unsigned long locked_vm
; /* Pages that have PG_mlocked set */
357 unsigned long pinned_vm
; /* Refcount permanently increased */
358 unsigned long shared_vm
; /* Shared pages (files) */
359 unsigned long exec_vm
; /* VM_EXEC & ~VM_WRITE */
360 unsigned long stack_vm
; /* VM_GROWSUP/DOWN */
361 unsigned long def_flags
;
362 unsigned long nr_ptes
; /* Page table pages */
363 unsigned long start_code
, end_code
, start_data
, end_data
;
364 unsigned long start_brk
, brk
, start_stack
;
365 unsigned long arg_start
, arg_end
, env_start
, env_end
;
367 unsigned long saved_auxv
[AT_VECTOR_SIZE
]; /* for /proc/PID/auxv */
370 * Special counters, in some configurations protected by the
371 * page_table_lock, in other configurations by being atomic.
373 struct mm_rss_stat rss_stat
;
375 struct linux_binfmt
*binfmt
;
377 cpumask_var_t cpu_vm_mask_var
;
379 /* Architecture-specific MM context */
380 mm_context_t context
;
382 unsigned long flags
; /* Must use atomic bitops to access the bits */
384 struct core_state
*core_state
; /* coredumping support */
386 spinlock_t ioctx_lock
;
387 struct kioctx_table __rcu
*ioctx_table
;
389 #ifdef CONFIG_MM_OWNER
391 * "owner" points to a task that is regarded as the canonical
392 * user/owner of this mm. All of the following must be true in
393 * order for it to be changed:
395 * current == mm->owner
397 * new_owner->mm == mm
398 * new_owner->alloc_lock is held
400 struct task_struct __rcu
*owner
;
403 /* store ref to file /proc/<pid>/exe symlink points to */
404 struct file
*exe_file
;
405 #ifdef CONFIG_MMU_NOTIFIER
406 struct mmu_notifier_mm
*mmu_notifier_mm
;
408 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
409 pgtable_t pmd_huge_pte
; /* protected by page_table_lock */
411 #ifdef CONFIG_CPUMASK_OFFSTACK
412 struct cpumask cpumask_allocation
;
414 #ifdef CONFIG_NUMA_BALANCING
416 * numa_next_scan is the next time that the PTEs will be marked
417 * pte_numa. NUMA hinting faults will gather statistics and migrate
418 * pages to new nodes if necessary.
420 unsigned long numa_next_scan
;
422 /* numa_next_reset is when the PTE scanner period will be reset */
423 unsigned long numa_next_reset
;
425 /* Restart point for scanning and setting pte_numa */
426 unsigned long numa_scan_offset
;
428 /* numa_scan_seq prevents two threads setting pte_numa */
432 * The first node a task was scheduled on. If a task runs on
433 * a different node than Make PTE Scan Go Now.
437 struct uprobes_state uprobes_state
;
440 /* first nid will either be a valid NID or one of these values */
441 #define NUMA_PTE_SCAN_INIT -1
442 #define NUMA_PTE_SCAN_ACTIVE -2
444 static inline void mm_init_cpumask(struct mm_struct
*mm
)
446 #ifdef CONFIG_CPUMASK_OFFSTACK
447 mm
->cpu_vm_mask_var
= &mm
->cpumask_allocation
;
451 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */
452 static inline cpumask_t
*mm_cpumask(struct mm_struct
*mm
)
454 return mm
->cpu_vm_mask_var
;
457 #endif /* _LINUX_MM_TYPES_H */