writeback: split writeback_inodes_wb
[linux-2.6/next.git] / include / linux / mm_types.h
blobb8bb9a6a1f37b71cae90c33ff84e75d2d780226a
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 <asm/page.h>
16 #include <asm/mmu.h>
18 #ifndef AT_VECTOR_SIZE_ARCH
19 #define AT_VECTOR_SIZE_ARCH 0
20 #endif
21 #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1))
23 struct address_space;
25 #define USE_SPLIT_PTLOCKS (NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS)
28 * Each physical page in the system has a struct page associated with
29 * it to keep track of whatever it is we are using the page for at the
30 * moment. Note that we have no way to track which tasks are using
31 * a page, though if it is a pagecache page, rmap structures can tell us
32 * who is mapping it.
34 struct page {
35 unsigned long flags; /* Atomic flags, some possibly
36 * updated asynchronously */
37 atomic_t _count; /* Usage count, see below. */
38 union {
39 atomic_t _mapcount; /* Count of ptes mapped in mms,
40 * to show when page is mapped
41 * & limit reverse map searches.
43 struct { /* SLUB */
44 u16 inuse;
45 u16 objects;
48 union {
49 struct {
50 unsigned long private; /* Mapping-private opaque data:
51 * usually used for buffer_heads
52 * if PagePrivate set; used for
53 * swp_entry_t if PageSwapCache;
54 * indicates order in the buddy
55 * system if PG_buddy is set.
57 struct address_space *mapping; /* If low bit clear, points to
58 * inode address_space, or NULL.
59 * If page mapped as anonymous
60 * memory, low bit is set, and
61 * it points to anon_vma object:
62 * see PAGE_MAPPING_ANON below.
65 #if USE_SPLIT_PTLOCKS
66 spinlock_t ptl;
67 #endif
68 struct kmem_cache *slab; /* SLUB: Pointer to slab */
69 struct page *first_page; /* Compound tail pages */
71 union {
72 pgoff_t index; /* Our offset within mapping. */
73 void *freelist; /* SLUB: freelist req. slab lock */
75 struct list_head lru; /* Pageout list, eg. active_list
76 * protected by zone->lru_lock !
79 * On machines where all RAM is mapped into kernel address space,
80 * we can simply calculate the virtual address. On machines with
81 * highmem some memory is mapped into kernel virtual memory
82 * dynamically, so we need a place to store that address.
83 * Note that this field could be 16 bits on x86 ... ;)
85 * Architectures with slow multiplication can define
86 * WANT_PAGE_VIRTUAL in asm/page.h
88 #if defined(WANT_PAGE_VIRTUAL)
89 void *virtual; /* Kernel virtual address (NULL if
90 not kmapped, ie. highmem) */
91 #endif /* WANT_PAGE_VIRTUAL */
92 #ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
93 unsigned long debug_flags; /* Use atomic bitops on this */
94 #endif
96 #ifdef CONFIG_KMEMCHECK
98 * kmemcheck wants to track the status of each byte in a page; this
99 * is a pointer to such a status block. NULL if not tracked.
101 void *shadow;
102 #endif
106 * A region containing a mapping of a non-memory backed file under NOMMU
107 * conditions. These are held in a global tree and are pinned by the VMAs that
108 * map parts of them.
110 struct vm_region {
111 struct rb_node vm_rb; /* link in global region tree */
112 unsigned long vm_flags; /* VMA vm_flags */
113 unsigned long vm_start; /* start address of region */
114 unsigned long vm_end; /* region initialised to here */
115 unsigned long vm_top; /* region allocated to here */
116 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */
117 struct file *vm_file; /* the backing file or NULL */
119 int vm_usage; /* region usage count (access under nommu_region_sem) */
120 bool vm_icache_flushed : 1; /* true if the icache has been flushed for
121 * this region */
125 * This struct defines a memory VMM memory area. There is one of these
126 * per VM-area/task. A VM area is any part of the process virtual memory
127 * space that has a special rule for the page-fault handlers (ie a shared
128 * library, the executable area etc).
130 struct vm_area_struct {
131 struct mm_struct * vm_mm; /* The address space we belong to. */
132 unsigned long vm_start; /* Our start address within vm_mm. */
133 unsigned long vm_end; /* The first byte after our end address
134 within vm_mm. */
136 /* linked list of VM areas per task, sorted by address */
137 struct vm_area_struct *vm_next;
139 pgprot_t vm_page_prot; /* Access permissions of this VMA. */
140 unsigned long vm_flags; /* Flags, see mm.h. */
142 struct rb_node vm_rb;
145 * For areas with an address space and backing store,
146 * linkage into the address_space->i_mmap prio tree, or
147 * linkage to the list of like vmas hanging off its node, or
148 * linkage of vma in the address_space->i_mmap_nonlinear list.
150 union {
151 struct {
152 struct list_head list;
153 void *parent; /* aligns with prio_tree_node parent */
154 struct vm_area_struct *head;
155 } vm_set;
157 struct raw_prio_tree_node prio_tree_node;
158 } shared;
161 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
162 * list, after a COW of one of the file pages. A MAP_SHARED vma
163 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack
164 * or brk vma (with NULL file) can only be in an anon_vma list.
166 struct list_head anon_vma_chain; /* Serialized by mmap_sem &
167 * page_table_lock */
168 struct anon_vma *anon_vma; /* Serialized by page_table_lock */
170 /* Function pointers to deal with this struct. */
171 const struct vm_operations_struct *vm_ops;
173 /* Information about our backing store: */
174 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE
175 units, *not* PAGE_CACHE_SIZE */
176 struct file * vm_file; /* File we map to (can be NULL). */
177 void * vm_private_data; /* was vm_pte (shared mem) */
178 unsigned long vm_truncate_count;/* truncate_count or restart_addr */
180 #ifndef CONFIG_MMU
181 struct vm_region *vm_region; /* NOMMU mapping region */
182 #endif
183 #ifdef CONFIG_NUMA
184 struct mempolicy *vm_policy; /* NUMA policy for the VMA */
185 #endif
188 struct core_thread {
189 struct task_struct *task;
190 struct core_thread *next;
193 struct core_state {
194 atomic_t nr_threads;
195 struct core_thread dumper;
196 struct completion startup;
199 enum {
200 MM_FILEPAGES,
201 MM_ANONPAGES,
202 MM_SWAPENTS,
203 NR_MM_COUNTERS
206 #if USE_SPLIT_PTLOCKS && defined(CONFIG_MMU)
207 #define SPLIT_RSS_COUNTING
208 struct mm_rss_stat {
209 atomic_long_t count[NR_MM_COUNTERS];
211 /* per-thread cached information, */
212 struct task_rss_stat {
213 int events; /* for synchronization threshold */
214 int count[NR_MM_COUNTERS];
216 #else /* !USE_SPLIT_PTLOCKS */
217 struct mm_rss_stat {
218 unsigned long count[NR_MM_COUNTERS];
220 #endif /* !USE_SPLIT_PTLOCKS */
222 struct mm_struct {
223 struct vm_area_struct * mmap; /* list of VMAs */
224 struct rb_root mm_rb;
225 struct vm_area_struct * mmap_cache; /* last find_vma result */
226 #ifdef CONFIG_MMU
227 unsigned long (*get_unmapped_area) (struct file *filp,
228 unsigned long addr, unsigned long len,
229 unsigned long pgoff, unsigned long flags);
230 void (*unmap_area) (struct mm_struct *mm, unsigned long addr);
231 #endif
232 unsigned long mmap_base; /* base of mmap area */
233 unsigned long task_size; /* size of task vm space */
234 unsigned long cached_hole_size; /* if non-zero, the largest hole below free_area_cache */
235 unsigned long free_area_cache; /* first hole of size cached_hole_size or larger */
236 pgd_t * pgd;
237 atomic_t mm_users; /* How many users with user space? */
238 atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */
239 int map_count; /* number of VMAs */
240 struct rw_semaphore mmap_sem;
241 spinlock_t page_table_lock; /* Protects page tables and some counters */
243 struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung
244 * together off init_mm.mmlist, and are protected
245 * by mmlist_lock
249 unsigned long hiwater_rss; /* High-watermark of RSS usage */
250 unsigned long hiwater_vm; /* High-water virtual memory usage */
252 unsigned long total_vm, locked_vm, shared_vm, exec_vm;
253 unsigned long stack_vm, reserved_vm, def_flags, nr_ptes;
254 unsigned long start_code, end_code, start_data, end_data;
255 unsigned long start_brk, brk, start_stack;
256 unsigned long arg_start, arg_end, env_start, env_end;
258 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
261 * Special counters, in some configurations protected by the
262 * page_table_lock, in other configurations by being atomic.
264 struct mm_rss_stat rss_stat;
266 struct linux_binfmt *binfmt;
268 cpumask_t cpu_vm_mask;
270 /* Architecture-specific MM context */
271 mm_context_t context;
273 /* Swap token stuff */
275 * Last value of global fault stamp as seen by this process.
276 * In other words, this value gives an indication of how long
277 * it has been since this task got the token.
278 * Look at mm/thrash.c
280 unsigned int faultstamp;
281 unsigned int token_priority;
282 unsigned int last_interval;
284 unsigned long flags; /* Must use atomic bitops to access the bits */
286 struct core_state *core_state; /* coredumping support */
287 #ifdef CONFIG_AIO
288 spinlock_t ioctx_lock;
289 struct hlist_head ioctx_list;
290 #endif
291 #ifdef CONFIG_MM_OWNER
293 * "owner" points to a task that is regarded as the canonical
294 * user/owner of this mm. All of the following must be true in
295 * order for it to be changed:
297 * current == mm->owner
298 * current->mm != mm
299 * new_owner->mm == mm
300 * new_owner->alloc_lock is held
302 struct task_struct *owner;
303 #endif
305 #ifdef CONFIG_PROC_FS
306 /* store ref to file /proc/<pid>/exe symlink points to */
307 struct file *exe_file;
308 unsigned long num_exe_file_vmas;
309 #endif
310 #ifdef CONFIG_MMU_NOTIFIER
311 struct mmu_notifier_mm *mmu_notifier_mm;
312 #endif
315 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */
316 #define mm_cpumask(mm) (&(mm)->cpu_vm_mask)
318 #endif /* _LINUX_MM_TYPES_H */