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/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 fields */
133 struct kmem_cache *slab_cache;
134 struct slab *slab_page;
138 /* Remainder is not double word aligned */
140 unsigned long private; /* Mapping-private opaque data:
141 * usually used for buffer_heads
142 * if PagePrivate set; used for
143 * swp_entry_t if PageSwapCache;
144 * indicates order in the buddy
145 * system if PG_buddy is set.
147 #if USE_SPLIT_PTLOCKS
150 struct kmem_cache *slab; /* SLUB: Pointer to slab */
151 struct page *first_page; /* Compound tail pages */
155 * On machines where all RAM is mapped into kernel address space,
156 * we can simply calculate the virtual address. On machines with
157 * highmem some memory is mapped into kernel virtual memory
158 * dynamically, so we need a place to store that address.
159 * Note that this field could be 16 bits on x86 ... ;)
161 * Architectures with slow multiplication can define
162 * WANT_PAGE_VIRTUAL in asm/page.h
164 #if defined(WANT_PAGE_VIRTUAL)
165 void *virtual; /* Kernel virtual address (NULL if
166 not kmapped, ie. highmem) */
167 #endif /* WANT_PAGE_VIRTUAL */
168 #ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
169 unsigned long debug_flags; /* Use atomic bitops on this */
172 #ifdef CONFIG_KMEMCHECK
174 * kmemcheck wants to track the status of each byte in a page; this
175 * is a pointer to such a status block. NULL if not tracked.
181 * The struct page can be forced to be double word aligned so that atomic ops
182 * on double words work. The SLUB allocator can make use of such a feature.
184 #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE
185 __aligned(2 * sizeof(unsigned long))
191 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
200 typedef unsigned long __nocast vm_flags_t;
203 * A region containing a mapping of a non-memory backed file under NOMMU
204 * conditions. These are held in a global tree and are pinned by the VMAs that
208 struct rb_node vm_rb; /* link in global region tree */
209 vm_flags_t vm_flags; /* VMA vm_flags */
210 unsigned long vm_start; /* start address of region */
211 unsigned long vm_end; /* region initialised to here */
212 unsigned long vm_top; /* region allocated to here */
213 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */
214 struct file *vm_file; /* the backing file or NULL */
216 int vm_usage; /* region usage count (access under nommu_region_sem) */
217 bool vm_icache_flushed : 1; /* true if the icache has been flushed for
222 * This struct defines a memory VMM memory area. There is one of these
223 * per VM-area/task. A VM area is any part of the process virtual memory
224 * space that has a special rule for the page-fault handlers (ie a shared
225 * library, the executable area etc).
227 struct vm_area_struct {
228 struct mm_struct * vm_mm; /* The address space we belong to. */
229 unsigned long vm_start; /* Our start address within vm_mm. */
230 unsigned long vm_end; /* The first byte after our end address
233 /* linked list of VM areas per task, sorted by address */
234 struct vm_area_struct *vm_next, *vm_prev;
236 pgprot_t vm_page_prot; /* Access permissions of this VMA. */
237 unsigned long vm_flags; /* Flags, see mm.h. */
239 struct rb_node vm_rb;
242 * For areas with an address space and backing store,
243 * linkage into the address_space->i_mmap prio tree, or
244 * linkage to the list of like vmas hanging off its node, or
245 * linkage of vma in the address_space->i_mmap_nonlinear list.
249 struct list_head list;
250 void *parent; /* aligns with prio_tree_node parent */
251 struct vm_area_struct *head;
254 struct raw_prio_tree_node prio_tree_node;
258 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
259 * list, after a COW of one of the file pages. A MAP_SHARED vma
260 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack
261 * or brk vma (with NULL file) can only be in an anon_vma list.
263 struct list_head anon_vma_chain; /* Serialized by mmap_sem &
265 struct anon_vma *anon_vma; /* Serialized by page_table_lock */
267 /* Function pointers to deal with this struct. */
268 const struct vm_operations_struct *vm_ops;
270 /* Information about our backing store: */
271 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE
272 units, *not* PAGE_CACHE_SIZE */
273 struct file * vm_file; /* File we map to (can be NULL). */
274 void * vm_private_data; /* was vm_pte (shared mem) */
277 struct vm_region *vm_region; /* NOMMU mapping region */
280 struct mempolicy *vm_policy; /* NUMA policy for the VMA */
285 struct task_struct *task;
286 struct core_thread *next;
291 struct core_thread dumper;
292 struct completion startup;
302 #if USE_SPLIT_PTLOCKS && defined(CONFIG_MMU)
303 #define SPLIT_RSS_COUNTING
304 /* per-thread cached information, */
305 struct task_rss_stat {
306 int events; /* for synchronization threshold */
307 int count[NR_MM_COUNTERS];
309 #endif /* USE_SPLIT_PTLOCKS */
312 atomic_long_t count[NR_MM_COUNTERS];
316 struct vm_area_struct * mmap; /* list of VMAs */
317 struct rb_root mm_rb;
318 struct vm_area_struct * mmap_cache; /* last find_vma result */
320 unsigned long (*get_unmapped_area) (struct file *filp,
321 unsigned long addr, unsigned long len,
322 unsigned long pgoff, unsigned long flags);
323 void (*unmap_area) (struct mm_struct *mm, unsigned long addr);
325 unsigned long mmap_base; /* base of mmap area */
326 unsigned long task_size; /* size of task vm space */
327 unsigned long cached_hole_size; /* if non-zero, the largest hole below free_area_cache */
328 unsigned long free_area_cache; /* first hole of size cached_hole_size or larger */
330 atomic_t mm_users; /* How many users with user space? */
331 atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */
332 int map_count; /* number of VMAs */
334 spinlock_t page_table_lock; /* Protects page tables and some counters */
335 struct rw_semaphore mmap_sem;
337 struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung
338 * together off init_mm.mmlist, and are protected
343 unsigned long hiwater_rss; /* High-watermark of RSS usage */
344 unsigned long hiwater_vm; /* High-water virtual memory usage */
346 unsigned long total_vm; /* Total pages mapped */
347 unsigned long locked_vm; /* Pages that have PG_mlocked set */
348 unsigned long pinned_vm; /* Refcount permanently increased */
349 unsigned long shared_vm; /* Shared pages (files) */
350 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE */
351 unsigned long stack_vm; /* VM_GROWSUP/DOWN */
352 unsigned long reserved_vm; /* VM_RESERVED|VM_IO pages */
353 unsigned long def_flags;
354 unsigned long nr_ptes; /* Page table pages */
355 unsigned long start_code, end_code, start_data, end_data;
356 unsigned long start_brk, brk, start_stack;
357 unsigned long arg_start, arg_end, env_start, env_end;
359 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
362 * Special counters, in some configurations protected by the
363 * page_table_lock, in other configurations by being atomic.
365 struct mm_rss_stat rss_stat;
367 struct linux_binfmt *binfmt;
369 cpumask_var_t cpu_vm_mask_var;
371 /* Architecture-specific MM context */
372 mm_context_t context;
374 unsigned long flags; /* Must use atomic bitops to access the bits */
376 struct core_state *core_state; /* coredumping support */
378 spinlock_t ioctx_lock;
379 struct hlist_head ioctx_list;
381 #ifdef CONFIG_MM_OWNER
383 * "owner" points to a task that is regarded as the canonical
384 * user/owner of this mm. All of the following must be true in
385 * order for it to be changed:
387 * current == mm->owner
389 * new_owner->mm == mm
390 * new_owner->alloc_lock is held
392 struct task_struct __rcu *owner;
395 /* store ref to file /proc/<pid>/exe symlink points to */
396 struct file *exe_file;
397 #ifdef CONFIG_MMU_NOTIFIER
398 struct mmu_notifier_mm *mmu_notifier_mm;
400 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
401 pgtable_t pmd_huge_pte; /* protected by page_table_lock */
403 #ifdef CONFIG_CPUMASK_OFFSTACK
404 struct cpumask cpumask_allocation;
406 struct uprobes_state uprobes_state;
409 static inline void mm_init_cpumask(struct mm_struct *mm)
411 #ifdef CONFIG_CPUMASK_OFFSTACK
412 mm->cpu_vm_mask_var = &mm->cpumask_allocation;
416 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */
417 static inline cpumask_t *mm_cpumask(struct mm_struct *mm)
419 return mm->cpu_vm_mask_var;
422 #endif /* _LINUX_MM_TYPES_H */