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_PTE_PTLOCKS (NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS)
27 #define USE_SPLIT_PMD_PTLOCKS (USE_SPLIT_PTE_PTLOCKS && \
28 IS_ENABLED(CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK))
31 * Each physical page in the system has a struct page associated with
32 * it to keep track of whatever it is we are using the page for at the
33 * moment. Note that we have no way to track which tasks are using
34 * a page, though if it is a pagecache page, rmap structures can tell us
37 * The objects in struct page are organized in double word blocks in
38 * order to allows us to use atomic double word operations on portions
39 * of struct page. That is currently only used by slub but the arrangement
40 * allows the use of atomic double word operations on the flags/mapping
41 * and lru list pointers also.
44 /* First double word block */
45 unsigned long flags; /* Atomic flags, some possibly
46 * updated asynchronously */
47 struct address_space *mapping; /* If low bit clear, points to
48 * inode address_space, or NULL.
49 * If page mapped as anonymous
50 * memory, low bit is set, and
51 * it points to anon_vma object:
52 * see PAGE_MAPPING_ANON below.
54 /* Second double word */
57 pgoff_t index; /* Our offset within mapping. */
58 void *freelist; /* slub/slob first free object */
59 bool pfmemalloc; /* If set by the page allocator,
60 * ALLOC_NO_WATERMARKS was set
61 * and the low watermark was not
62 * met implying that the system
63 * is under some pressure. The
64 * caller should try ensure
65 * this page is only used to
68 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && USE_SPLIT_PMD_PTLOCKS
69 pgtable_t pmd_huge_pte; /* protected by page->ptl */
74 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
75 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
76 /* Used for cmpxchg_double in slub */
77 unsigned long counters;
80 * Keep _count separate from slub cmpxchg_double data.
81 * As the rest of the double word is protected by
82 * slab_lock but _count is not.
91 * Count of ptes mapped in
92 * mms, to show when page is
93 * mapped & limit reverse map
96 * Used also for tail pages
97 * refcounting instead of
98 * _count. Tail pages cannot
99 * be mapped and keeping the
100 * tail page _count zero at
101 * all times guarantees
102 * get_page_unless_zero() will
103 * never succeed on tail
113 int units; /* SLOB */
115 atomic_t _count; /* Usage count, see below. */
120 /* Third double word block */
122 struct list_head lru; /* Pageout list, eg. active_list
123 * protected by zone->lru_lock !
125 struct { /* slub per cpu partial pages */
126 struct page *next; /* Next partial slab */
128 int pages; /* Nr of partial slabs left */
129 int pobjects; /* Approximate # of objects */
136 struct list_head list; /* slobs list of pages */
137 struct slab *slab_page; /* slab fields */
140 /* Remainder is not double word aligned */
142 unsigned long private; /* Mapping-private opaque data:
143 * usually used for buffer_heads
144 * if PagePrivate set; used for
145 * swp_entry_t if PageSwapCache;
146 * indicates order in the buddy
147 * system if PG_buddy is set.
149 #if USE_SPLIT_PTE_PTLOCKS
150 unsigned long ptl; /* It's spinlock_t if it fits to long,
151 * otherwise it's pointer to dynamicaly
152 * allocated spinlock_t.
155 struct kmem_cache *slab_cache; /* SL[AU]B: Pointer to slab */
156 struct page *first_page; /* Compound tail pages */
160 * On machines where all RAM is mapped into kernel address space,
161 * we can simply calculate the virtual address. On machines with
162 * highmem some memory is mapped into kernel virtual memory
163 * dynamically, so we need a place to store that address.
164 * Note that this field could be 16 bits on x86 ... ;)
166 * Architectures with slow multiplication can define
167 * WANT_PAGE_VIRTUAL in asm/page.h
169 #if defined(WANT_PAGE_VIRTUAL)
170 void *virtual; /* Kernel virtual address (NULL if
171 not kmapped, ie. highmem) */
172 #endif /* WANT_PAGE_VIRTUAL */
173 #ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
174 unsigned long debug_flags; /* Use atomic bitops on this */
177 #ifdef CONFIG_KMEMCHECK
179 * kmemcheck wants to track the status of each byte in a page; this
180 * is a pointer to such a status block. NULL if not tracked.
185 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
190 * The struct page can be forced to be double word aligned so that atomic ops
191 * on double words work. The SLUB allocator can make use of such a feature.
193 #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE
194 __aligned(2 * sizeof(unsigned long))
200 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
209 typedef unsigned long __nocast vm_flags_t;
212 * A region containing a mapping of a non-memory backed file under NOMMU
213 * conditions. These are held in a global tree and are pinned by the VMAs that
217 struct rb_node vm_rb; /* link in global region tree */
218 vm_flags_t vm_flags; /* VMA vm_flags */
219 unsigned long vm_start; /* start address of region */
220 unsigned long vm_end; /* region initialised to here */
221 unsigned long vm_top; /* region allocated to here */
222 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */
223 struct file *vm_file; /* the backing file or NULL */
225 int vm_usage; /* region usage count (access under nommu_region_sem) */
226 bool vm_icache_flushed : 1; /* true if the icache has been flushed for
231 * This struct defines a memory VMM memory area. There is one of these
232 * per VM-area/task. A VM area is any part of the process virtual memory
233 * space that has a special rule for the page-fault handlers (ie a shared
234 * library, the executable area etc).
236 struct vm_area_struct {
237 /* The first cache line has the info for VMA tree walking. */
239 unsigned long vm_start; /* Our start address within vm_mm. */
240 unsigned long vm_end; /* The first byte after our end address
243 /* linked list of VM areas per task, sorted by address */
244 struct vm_area_struct *vm_next, *vm_prev;
246 struct rb_node vm_rb;
249 * Largest free memory gap in bytes to the left of this VMA.
250 * Either between this VMA and vma->vm_prev, or between one of the
251 * VMAs below us in the VMA rbtree and its ->vm_prev. This helps
252 * get_unmapped_area find a free area of the right size.
254 unsigned long rb_subtree_gap;
256 /* Second cache line starts here. */
258 struct mm_struct *vm_mm; /* The address space we belong to. */
259 pgprot_t vm_page_prot; /* Access permissions of this VMA. */
260 unsigned long vm_flags; /* Flags, see mm.h. */
263 * For areas with an address space and backing store,
264 * linkage into the address_space->i_mmap interval tree, or
265 * linkage of vma in the address_space->i_mmap_nonlinear list.
270 unsigned long rb_subtree_last;
272 struct list_head nonlinear;
276 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
277 * list, after a COW of one of the file pages. A MAP_SHARED vma
278 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack
279 * or brk vma (with NULL file) can only be in an anon_vma list.
281 struct list_head anon_vma_chain; /* Serialized by mmap_sem &
283 struct anon_vma *anon_vma; /* Serialized by page_table_lock */
285 /* Function pointers to deal with this struct. */
286 const struct vm_operations_struct *vm_ops;
288 /* Information about our backing store: */
289 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE
290 units, *not* PAGE_CACHE_SIZE */
291 struct file * vm_file; /* File we map to (can be NULL). */
292 void * vm_private_data; /* was vm_pte (shared mem) */
295 struct vm_region *vm_region; /* NOMMU mapping region */
298 struct mempolicy *vm_policy; /* NUMA policy for the VMA */
303 struct task_struct *task;
304 struct core_thread *next;
309 struct core_thread dumper;
310 struct completion startup;
320 #if USE_SPLIT_PTE_PTLOCKS && defined(CONFIG_MMU)
321 #define SPLIT_RSS_COUNTING
322 /* per-thread cached information, */
323 struct task_rss_stat {
324 int events; /* for synchronization threshold */
325 int count[NR_MM_COUNTERS];
327 #endif /* USE_SPLIT_PTE_PTLOCKS */
330 atomic_long_t count[NR_MM_COUNTERS];
335 struct vm_area_struct * mmap; /* list of VMAs */
336 struct rb_root mm_rb;
337 struct vm_area_struct * mmap_cache; /* last find_vma result */
339 unsigned long (*get_unmapped_area) (struct file *filp,
340 unsigned long addr, unsigned long len,
341 unsigned long pgoff, unsigned long flags);
343 unsigned long mmap_base; /* base of mmap area */
344 unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */
345 unsigned long task_size; /* size of task vm space */
346 unsigned long highest_vm_end; /* highest vma end address */
348 atomic_t mm_users; /* How many users with user space? */
349 atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */
350 atomic_long_t nr_ptes; /* Page table pages */
351 int map_count; /* number of VMAs */
353 spinlock_t page_table_lock; /* Protects page tables and some counters */
354 struct rw_semaphore mmap_sem;
356 struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung
357 * together off init_mm.mmlist, and are protected
362 unsigned long hiwater_rss; /* High-watermark of RSS usage */
363 unsigned long hiwater_vm; /* High-water virtual memory usage */
365 unsigned long total_vm; /* Total pages mapped */
366 unsigned long locked_vm; /* Pages that have PG_mlocked set */
367 unsigned long pinned_vm; /* Refcount permanently increased */
368 unsigned long shared_vm; /* Shared pages (files) */
369 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE */
370 unsigned long stack_vm; /* VM_GROWSUP/DOWN */
371 unsigned long def_flags;
372 unsigned long start_code, end_code, start_data, end_data;
373 unsigned long start_brk, brk, start_stack;
374 unsigned long arg_start, arg_end, env_start, env_end;
376 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
379 * Special counters, in some configurations protected by the
380 * page_table_lock, in other configurations by being atomic.
382 struct mm_rss_stat rss_stat;
384 struct linux_binfmt *binfmt;
386 cpumask_var_t cpu_vm_mask_var;
388 /* Architecture-specific MM context */
389 mm_context_t context;
391 unsigned long flags; /* Must use atomic bitops to access the bits */
393 struct core_state *core_state; /* coredumping support */
395 spinlock_t ioctx_lock;
396 struct kioctx_table __rcu *ioctx_table;
398 #ifdef CONFIG_MM_OWNER
400 * "owner" points to a task that is regarded as the canonical
401 * user/owner of this mm. All of the following must be true in
402 * order for it to be changed:
404 * current == mm->owner
406 * new_owner->mm == mm
407 * new_owner->alloc_lock is held
409 struct task_struct __rcu *owner;
412 /* store ref to file /proc/<pid>/exe symlink points to */
413 struct file *exe_file;
414 #ifdef CONFIG_MMU_NOTIFIER
415 struct mmu_notifier_mm *mmu_notifier_mm;
417 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
418 pgtable_t pmd_huge_pte; /* protected by page_table_lock */
420 #ifdef CONFIG_CPUMASK_OFFSTACK
421 struct cpumask cpumask_allocation;
423 #ifdef CONFIG_NUMA_BALANCING
425 * numa_next_scan is the next time that the PTEs will be marked
426 * pte_numa. NUMA hinting faults will gather statistics and migrate
427 * pages to new nodes if necessary.
429 unsigned long numa_next_scan;
431 /* Restart point for scanning and setting pte_numa */
432 unsigned long numa_scan_offset;
434 /* numa_scan_seq prevents two threads setting pte_numa */
437 struct uprobes_state uprobes_state;
440 static inline void mm_init_cpumask(struct mm_struct *mm)
442 #ifdef CONFIG_CPUMASK_OFFSTACK
443 mm->cpu_vm_mask_var = &mm->cpumask_allocation;
447 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */
448 static inline cpumask_t *mm_cpumask(struct mm_struct *mm)
450 return mm->cpu_vm_mask_var;
453 #endif /* _LINUX_MM_TYPES_H */