xref: /linux/mm/internal.h (revision 5bbfea1eacdf584d0d159e38c01ee190162706d9)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* internal.h: mm/ internal definitions
3  *
4  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 #ifndef __MM_INTERNAL_H
8 #define __MM_INTERNAL_H
9 
10 #include <linux/fs.h>
11 #include <linux/mm.h>
12 #include <linux/pagemap.h>
13 #include <linux/tracepoint-defs.h>
14 
15 /*
16  * The set of flags that only affect watermark checking and reclaim
17  * behaviour. This is used by the MM to obey the caller constraints
18  * about IO, FS and watermark checking while ignoring placement
19  * hints such as HIGHMEM usage.
20  */
21 #define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\
22 			__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NOFAIL|\
23 			__GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\
24 			__GFP_ATOMIC)
25 
26 /* The GFP flags allowed during early boot */
27 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS))
28 
29 /* Control allocation cpuset and node placement constraints */
30 #define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
31 
32 /* Do not use these with a slab allocator */
33 #define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
34 
35 void page_writeback_init(void);
36 
37 vm_fault_t do_swap_page(struct vm_fault *vmf);
38 
39 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
40 		unsigned long floor, unsigned long ceiling);
41 
42 static inline bool can_madv_lru_vma(struct vm_area_struct *vma)
43 {
44 	return !(vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP));
45 }
46 
47 void unmap_page_range(struct mmu_gather *tlb,
48 			     struct vm_area_struct *vma,
49 			     unsigned long addr, unsigned long end,
50 			     struct zap_details *details);
51 
52 void do_page_cache_ra(struct readahead_control *, unsigned long nr_to_read,
53 		unsigned long lookahead_size);
54 void force_page_cache_ra(struct readahead_control *, unsigned long nr);
55 static inline void force_page_cache_readahead(struct address_space *mapping,
56 		struct file *file, pgoff_t index, unsigned long nr_to_read)
57 {
58 	DEFINE_READAHEAD(ractl, file, &file->f_ra, mapping, index);
59 	force_page_cache_ra(&ractl, nr_to_read);
60 }
61 
62 unsigned find_lock_entries(struct address_space *mapping, pgoff_t start,
63 		pgoff_t end, struct pagevec *pvec, pgoff_t *indices);
64 
65 /**
66  * page_evictable - test whether a page is evictable
67  * @page: the page to test
68  *
69  * Test whether page is evictable--i.e., should be placed on active/inactive
70  * lists vs unevictable list.
71  *
72  * Reasons page might not be evictable:
73  * (1) page's mapping marked unevictable
74  * (2) page is part of an mlocked VMA
75  *
76  */
77 static inline bool page_evictable(struct page *page)
78 {
79 	bool ret;
80 
81 	/* Prevent address_space of inode and swap cache from being freed */
82 	rcu_read_lock();
83 	ret = !mapping_unevictable(page_mapping(page)) && !PageMlocked(page);
84 	rcu_read_unlock();
85 	return ret;
86 }
87 
88 /*
89  * Turn a non-refcounted page (->_refcount == 0) into refcounted with
90  * a count of one.
91  */
92 static inline void set_page_refcounted(struct page *page)
93 {
94 	VM_BUG_ON_PAGE(PageTail(page), page);
95 	VM_BUG_ON_PAGE(page_ref_count(page), page);
96 	set_page_count(page, 1);
97 }
98 
99 extern unsigned long highest_memmap_pfn;
100 
101 /*
102  * Maximum number of reclaim retries without progress before the OOM
103  * killer is consider the only way forward.
104  */
105 #define MAX_RECLAIM_RETRIES 16
106 
107 /*
108  * in mm/vmscan.c:
109  */
110 extern int isolate_lru_page(struct page *page);
111 extern void putback_lru_page(struct page *page);
112 
113 /*
114  * in mm/rmap.c:
115  */
116 extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
117 
118 /*
119  * in mm/memcontrol.c:
120  */
121 extern bool cgroup_memory_nokmem;
122 
123 /*
124  * in mm/page_alloc.c
125  */
126 
127 /*
128  * Structure for holding the mostly immutable allocation parameters passed
129  * between functions involved in allocations, including the alloc_pages*
130  * family of functions.
131  *
132  * nodemask, migratetype and highest_zoneidx are initialized only once in
133  * __alloc_pages() and then never change.
134  *
135  * zonelist, preferred_zone and highest_zoneidx are set first in
136  * __alloc_pages() for the fast path, and might be later changed
137  * in __alloc_pages_slowpath(). All other functions pass the whole structure
138  * by a const pointer.
139  */
140 struct alloc_context {
141 	struct zonelist *zonelist;
142 	nodemask_t *nodemask;
143 	struct zoneref *preferred_zoneref;
144 	int migratetype;
145 
146 	/*
147 	 * highest_zoneidx represents highest usable zone index of
148 	 * the allocation request. Due to the nature of the zone,
149 	 * memory on lower zone than the highest_zoneidx will be
150 	 * protected by lowmem_reserve[highest_zoneidx].
151 	 *
152 	 * highest_zoneidx is also used by reclaim/compaction to limit
153 	 * the target zone since higher zone than this index cannot be
154 	 * usable for this allocation request.
155 	 */
156 	enum zone_type highest_zoneidx;
157 	bool spread_dirty_pages;
158 };
159 
160 /*
161  * Locate the struct page for both the matching buddy in our
162  * pair (buddy1) and the combined O(n+1) page they form (page).
163  *
164  * 1) Any buddy B1 will have an order O twin B2 which satisfies
165  * the following equation:
166  *     B2 = B1 ^ (1 << O)
167  * For example, if the starting buddy (buddy2) is #8 its order
168  * 1 buddy is #10:
169  *     B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
170  *
171  * 2) Any buddy B will have an order O+1 parent P which
172  * satisfies the following equation:
173  *     P = B & ~(1 << O)
174  *
175  * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
176  */
177 static inline unsigned long
178 __find_buddy_pfn(unsigned long page_pfn, unsigned int order)
179 {
180 	return page_pfn ^ (1 << order);
181 }
182 
183 extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
184 				unsigned long end_pfn, struct zone *zone);
185 
186 static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn,
187 				unsigned long end_pfn, struct zone *zone)
188 {
189 	if (zone->contiguous)
190 		return pfn_to_page(start_pfn);
191 
192 	return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);
193 }
194 
195 extern int __isolate_free_page(struct page *page, unsigned int order);
196 extern void __putback_isolated_page(struct page *page, unsigned int order,
197 				    int mt);
198 extern void memblock_free_pages(struct page *page, unsigned long pfn,
199 					unsigned int order);
200 extern void __free_pages_core(struct page *page, unsigned int order);
201 extern void prep_compound_page(struct page *page, unsigned int order);
202 extern void post_alloc_hook(struct page *page, unsigned int order,
203 					gfp_t gfp_flags);
204 extern int user_min_free_kbytes;
205 
206 extern void free_unref_page(struct page *page, unsigned int order);
207 extern void free_unref_page_list(struct list_head *list);
208 
209 extern void zone_pcp_update(struct zone *zone, int cpu_online);
210 extern void zone_pcp_reset(struct zone *zone);
211 extern void zone_pcp_disable(struct zone *zone);
212 extern void zone_pcp_enable(struct zone *zone);
213 
214 extern void *memmap_alloc(phys_addr_t size, phys_addr_t align,
215 			  phys_addr_t min_addr,
216 			  int nid, bool exact_nid);
217 
218 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
219 
220 /*
221  * in mm/compaction.c
222  */
223 /*
224  * compact_control is used to track pages being migrated and the free pages
225  * they are being migrated to during memory compaction. The free_pfn starts
226  * at the end of a zone and migrate_pfn begins at the start. Movable pages
227  * are moved to the end of a zone during a compaction run and the run
228  * completes when free_pfn <= migrate_pfn
229  */
230 struct compact_control {
231 	struct list_head freepages;	/* List of free pages to migrate to */
232 	struct list_head migratepages;	/* List of pages being migrated */
233 	unsigned int nr_freepages;	/* Number of isolated free pages */
234 	unsigned int nr_migratepages;	/* Number of pages to migrate */
235 	unsigned long free_pfn;		/* isolate_freepages search base */
236 	/*
237 	 * Acts as an in/out parameter to page isolation for migration.
238 	 * isolate_migratepages uses it as a search base.
239 	 * isolate_migratepages_block will update the value to the next pfn
240 	 * after the last isolated one.
241 	 */
242 	unsigned long migrate_pfn;
243 	unsigned long fast_start_pfn;	/* a pfn to start linear scan from */
244 	struct zone *zone;
245 	unsigned long total_migrate_scanned;
246 	unsigned long total_free_scanned;
247 	unsigned short fast_search_fail;/* failures to use free list searches */
248 	short search_order;		/* order to start a fast search at */
249 	const gfp_t gfp_mask;		/* gfp mask of a direct compactor */
250 	int order;			/* order a direct compactor needs */
251 	int migratetype;		/* migratetype of direct compactor */
252 	const unsigned int alloc_flags;	/* alloc flags of a direct compactor */
253 	const int highest_zoneidx;	/* zone index of a direct compactor */
254 	enum migrate_mode mode;		/* Async or sync migration mode */
255 	bool ignore_skip_hint;		/* Scan blocks even if marked skip */
256 	bool no_set_skip_hint;		/* Don't mark blocks for skipping */
257 	bool ignore_block_suitable;	/* Scan blocks considered unsuitable */
258 	bool direct_compaction;		/* False from kcompactd or /proc/... */
259 	bool proactive_compaction;	/* kcompactd proactive compaction */
260 	bool whole_zone;		/* Whole zone should/has been scanned */
261 	bool contended;			/* Signal lock or sched contention */
262 	bool rescan;			/* Rescanning the same pageblock */
263 	bool alloc_contig;		/* alloc_contig_range allocation */
264 };
265 
266 /*
267  * Used in direct compaction when a page should be taken from the freelists
268  * immediately when one is created during the free path.
269  */
270 struct capture_control {
271 	struct compact_control *cc;
272 	struct page *page;
273 };
274 
275 unsigned long
276 isolate_freepages_range(struct compact_control *cc,
277 			unsigned long start_pfn, unsigned long end_pfn);
278 int
279 isolate_migratepages_range(struct compact_control *cc,
280 			   unsigned long low_pfn, unsigned long end_pfn);
281 #endif
282 int find_suitable_fallback(struct free_area *area, unsigned int order,
283 			int migratetype, bool only_stealable, bool *can_steal);
284 
285 /*
286  * This function returns the order of a free page in the buddy system. In
287  * general, page_zone(page)->lock must be held by the caller to prevent the
288  * page from being allocated in parallel and returning garbage as the order.
289  * If a caller does not hold page_zone(page)->lock, it must guarantee that the
290  * page cannot be allocated or merged in parallel. Alternatively, it must
291  * handle invalid values gracefully, and use buddy_order_unsafe() below.
292  */
293 static inline unsigned int buddy_order(struct page *page)
294 {
295 	/* PageBuddy() must be checked by the caller */
296 	return page_private(page);
297 }
298 
299 /*
300  * Like buddy_order(), but for callers who cannot afford to hold the zone lock.
301  * PageBuddy() should be checked first by the caller to minimize race window,
302  * and invalid values must be handled gracefully.
303  *
304  * READ_ONCE is used so that if the caller assigns the result into a local
305  * variable and e.g. tests it for valid range before using, the compiler cannot
306  * decide to remove the variable and inline the page_private(page) multiple
307  * times, potentially observing different values in the tests and the actual
308  * use of the result.
309  */
310 #define buddy_order_unsafe(page)	READ_ONCE(page_private(page))
311 
312 /*
313  * These three helpers classifies VMAs for virtual memory accounting.
314  */
315 
316 /*
317  * Executable code area - executable, not writable, not stack
318  */
319 static inline bool is_exec_mapping(vm_flags_t flags)
320 {
321 	return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC;
322 }
323 
324 /*
325  * Stack area - automatically grows in one direction
326  *
327  * VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous:
328  * do_mmap() forbids all other combinations.
329  */
330 static inline bool is_stack_mapping(vm_flags_t flags)
331 {
332 	return (flags & VM_STACK) == VM_STACK;
333 }
334 
335 /*
336  * Data area - private, writable, not stack
337  */
338 static inline bool is_data_mapping(vm_flags_t flags)
339 {
340 	return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE;
341 }
342 
343 /* mm/util.c */
344 void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
345 		struct vm_area_struct *prev);
346 void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma);
347 
348 #ifdef CONFIG_MMU
349 extern long populate_vma_page_range(struct vm_area_struct *vma,
350 		unsigned long start, unsigned long end, int *locked);
351 extern long faultin_vma_page_range(struct vm_area_struct *vma,
352 				   unsigned long start, unsigned long end,
353 				   bool write, int *locked);
354 extern void munlock_vma_pages_range(struct vm_area_struct *vma,
355 			unsigned long start, unsigned long end);
356 static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
357 {
358 	munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
359 }
360 
361 /*
362  * must be called with vma's mmap_lock held for read or write, and page locked.
363  */
364 extern void mlock_vma_page(struct page *page);
365 extern unsigned int munlock_vma_page(struct page *page);
366 
367 extern int mlock_future_check(struct mm_struct *mm, unsigned long flags,
368 			      unsigned long len);
369 
370 /*
371  * Clear the page's PageMlocked().  This can be useful in a situation where
372  * we want to unconditionally remove a page from the pagecache -- e.g.,
373  * on truncation or freeing.
374  *
375  * It is legal to call this function for any page, mlocked or not.
376  * If called for a page that is still mapped by mlocked vmas, all we do
377  * is revert to lazy LRU behaviour -- semantics are not broken.
378  */
379 extern void clear_page_mlock(struct page *page);
380 
381 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
382 
383 /*
384  * At what user virtual address is page expected in vma?
385  * Returns -EFAULT if all of the page is outside the range of vma.
386  * If page is a compound head, the entire compound page is considered.
387  */
388 static inline unsigned long
389 vma_address(struct page *page, struct vm_area_struct *vma)
390 {
391 	pgoff_t pgoff;
392 	unsigned long address;
393 
394 	VM_BUG_ON_PAGE(PageKsm(page), page);	/* KSM page->index unusable */
395 	pgoff = page_to_pgoff(page);
396 	if (pgoff >= vma->vm_pgoff) {
397 		address = vma->vm_start +
398 			((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
399 		/* Check for address beyond vma (or wrapped through 0?) */
400 		if (address < vma->vm_start || address >= vma->vm_end)
401 			address = -EFAULT;
402 	} else if (PageHead(page) &&
403 		   pgoff + compound_nr(page) - 1 >= vma->vm_pgoff) {
404 		/* Test above avoids possibility of wrap to 0 on 32-bit */
405 		address = vma->vm_start;
406 	} else {
407 		address = -EFAULT;
408 	}
409 	return address;
410 }
411 
412 /*
413  * Then at what user virtual address will none of the page be found in vma?
414  * Assumes that vma_address() already returned a good starting address.
415  * If page is a compound head, the entire compound page is considered.
416  */
417 static inline unsigned long
418 vma_address_end(struct page *page, struct vm_area_struct *vma)
419 {
420 	pgoff_t pgoff;
421 	unsigned long address;
422 
423 	VM_BUG_ON_PAGE(PageKsm(page), page);	/* KSM page->index unusable */
424 	pgoff = page_to_pgoff(page) + compound_nr(page);
425 	address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
426 	/* Check for address beyond vma (or wrapped through 0?) */
427 	if (address < vma->vm_start || address > vma->vm_end)
428 		address = vma->vm_end;
429 	return address;
430 }
431 
432 static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf,
433 						    struct file *fpin)
434 {
435 	int flags = vmf->flags;
436 
437 	if (fpin)
438 		return fpin;
439 
440 	/*
441 	 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or
442 	 * anything, so we only pin the file and drop the mmap_lock if only
443 	 * FAULT_FLAG_ALLOW_RETRY is set, while this is the first attempt.
444 	 */
445 	if (fault_flag_allow_retry_first(flags) &&
446 	    !(flags & FAULT_FLAG_RETRY_NOWAIT)) {
447 		fpin = get_file(vmf->vma->vm_file);
448 		mmap_read_unlock(vmf->vma->vm_mm);
449 	}
450 	return fpin;
451 }
452 
453 #else /* !CONFIG_MMU */
454 static inline void clear_page_mlock(struct page *page) { }
455 static inline void mlock_vma_page(struct page *page) { }
456 static inline void vunmap_range_noflush(unsigned long start, unsigned long end)
457 {
458 }
459 #endif /* !CONFIG_MMU */
460 
461 /*
462  * Return the mem_map entry representing the 'offset' subpage within
463  * the maximally aligned gigantic page 'base'.  Handle any discontiguity
464  * in the mem_map at MAX_ORDER_NR_PAGES boundaries.
465  */
466 static inline struct page *mem_map_offset(struct page *base, int offset)
467 {
468 	if (unlikely(offset >= MAX_ORDER_NR_PAGES))
469 		return nth_page(base, offset);
470 	return base + offset;
471 }
472 
473 /*
474  * Iterator over all subpages within the maximally aligned gigantic
475  * page 'base'.  Handle any discontiguity in the mem_map.
476  */
477 static inline struct page *mem_map_next(struct page *iter,
478 						struct page *base, int offset)
479 {
480 	if (unlikely((offset & (MAX_ORDER_NR_PAGES - 1)) == 0)) {
481 		unsigned long pfn = page_to_pfn(base) + offset;
482 		if (!pfn_valid(pfn))
483 			return NULL;
484 		return pfn_to_page(pfn);
485 	}
486 	return iter + 1;
487 }
488 
489 /* Memory initialisation debug and verification */
490 enum mminit_level {
491 	MMINIT_WARNING,
492 	MMINIT_VERIFY,
493 	MMINIT_TRACE
494 };
495 
496 #ifdef CONFIG_DEBUG_MEMORY_INIT
497 
498 extern int mminit_loglevel;
499 
500 #define mminit_dprintk(level, prefix, fmt, arg...) \
501 do { \
502 	if (level < mminit_loglevel) { \
503 		if (level <= MMINIT_WARNING) \
504 			pr_warn("mminit::" prefix " " fmt, ##arg);	\
505 		else \
506 			printk(KERN_DEBUG "mminit::" prefix " " fmt, ##arg); \
507 	} \
508 } while (0)
509 
510 extern void mminit_verify_pageflags_layout(void);
511 extern void mminit_verify_zonelist(void);
512 #else
513 
514 static inline void mminit_dprintk(enum mminit_level level,
515 				const char *prefix, const char *fmt, ...)
516 {
517 }
518 
519 static inline void mminit_verify_pageflags_layout(void)
520 {
521 }
522 
523 static inline void mminit_verify_zonelist(void)
524 {
525 }
526 #endif /* CONFIG_DEBUG_MEMORY_INIT */
527 
528 /* mminit_validate_memmodel_limits is independent of CONFIG_DEBUG_MEMORY_INIT */
529 #if defined(CONFIG_SPARSEMEM)
530 extern void mminit_validate_memmodel_limits(unsigned long *start_pfn,
531 				unsigned long *end_pfn);
532 #else
533 static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
534 				unsigned long *end_pfn)
535 {
536 }
537 #endif /* CONFIG_SPARSEMEM */
538 
539 #define NODE_RECLAIM_NOSCAN	-2
540 #define NODE_RECLAIM_FULL	-1
541 #define NODE_RECLAIM_SOME	0
542 #define NODE_RECLAIM_SUCCESS	1
543 
544 #ifdef CONFIG_NUMA
545 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
546 extern int find_next_best_node(int node, nodemask_t *used_node_mask);
547 #else
548 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
549 				unsigned int order)
550 {
551 	return NODE_RECLAIM_NOSCAN;
552 }
553 static inline int find_next_best_node(int node, nodemask_t *used_node_mask)
554 {
555 	return NUMA_NO_NODE;
556 }
557 #endif
558 
559 extern int hwpoison_filter(struct page *p);
560 
561 extern u32 hwpoison_filter_dev_major;
562 extern u32 hwpoison_filter_dev_minor;
563 extern u64 hwpoison_filter_flags_mask;
564 extern u64 hwpoison_filter_flags_value;
565 extern u64 hwpoison_filter_memcg;
566 extern u32 hwpoison_filter_enable;
567 
568 extern unsigned long  __must_check vm_mmap_pgoff(struct file *, unsigned long,
569         unsigned long, unsigned long,
570         unsigned long, unsigned long);
571 
572 extern void set_pageblock_order(void);
573 unsigned int reclaim_clean_pages_from_list(struct zone *zone,
574 					    struct list_head *page_list);
575 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
576 #define ALLOC_WMARK_MIN		WMARK_MIN
577 #define ALLOC_WMARK_LOW		WMARK_LOW
578 #define ALLOC_WMARK_HIGH	WMARK_HIGH
579 #define ALLOC_NO_WATERMARKS	0x04 /* don't check watermarks at all */
580 
581 /* Mask to get the watermark bits */
582 #define ALLOC_WMARK_MASK	(ALLOC_NO_WATERMARKS-1)
583 
584 /*
585  * Only MMU archs have async oom victim reclaim - aka oom_reaper so we
586  * cannot assume a reduced access to memory reserves is sufficient for
587  * !MMU
588  */
589 #ifdef CONFIG_MMU
590 #define ALLOC_OOM		0x08
591 #else
592 #define ALLOC_OOM		ALLOC_NO_WATERMARKS
593 #endif
594 
595 #define ALLOC_HARDER		 0x10 /* try to alloc harder */
596 #define ALLOC_HIGH		 0x20 /* __GFP_HIGH set */
597 #define ALLOC_CPUSET		 0x40 /* check for correct cpuset */
598 #define ALLOC_CMA		 0x80 /* allow allocations from CMA areas */
599 #ifdef CONFIG_ZONE_DMA32
600 #define ALLOC_NOFRAGMENT	0x100 /* avoid mixing pageblock types */
601 #else
602 #define ALLOC_NOFRAGMENT	  0x0
603 #endif
604 #define ALLOC_KSWAPD		0x800 /* allow waking of kswapd, __GFP_KSWAPD_RECLAIM set */
605 
606 enum ttu_flags;
607 struct tlbflush_unmap_batch;
608 
609 
610 /*
611  * only for MM internal work items which do not depend on
612  * any allocations or locks which might depend on allocations
613  */
614 extern struct workqueue_struct *mm_percpu_wq;
615 
616 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
617 void try_to_unmap_flush(void);
618 void try_to_unmap_flush_dirty(void);
619 void flush_tlb_batched_pending(struct mm_struct *mm);
620 #else
621 static inline void try_to_unmap_flush(void)
622 {
623 }
624 static inline void try_to_unmap_flush_dirty(void)
625 {
626 }
627 static inline void flush_tlb_batched_pending(struct mm_struct *mm)
628 {
629 }
630 #endif /* CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH */
631 
632 extern const struct trace_print_flags pageflag_names[];
633 extern const struct trace_print_flags vmaflag_names[];
634 extern const struct trace_print_flags gfpflag_names[];
635 
636 static inline bool is_migrate_highatomic(enum migratetype migratetype)
637 {
638 	return migratetype == MIGRATE_HIGHATOMIC;
639 }
640 
641 static inline bool is_migrate_highatomic_page(struct page *page)
642 {
643 	return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC;
644 }
645 
646 void setup_zone_pageset(struct zone *zone);
647 
648 struct migration_target_control {
649 	int nid;		/* preferred node id */
650 	nodemask_t *nmask;
651 	gfp_t gfp_mask;
652 };
653 
654 /*
655  * mm/vmalloc.c
656  */
657 #ifdef CONFIG_MMU
658 int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
659                 pgprot_t prot, struct page **pages, unsigned int page_shift);
660 #else
661 static inline
662 int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
663                 pgprot_t prot, struct page **pages, unsigned int page_shift)
664 {
665 	return -EINVAL;
666 }
667 #endif
668 
669 void vunmap_range_noflush(unsigned long start, unsigned long end);
670 
671 int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
672 		      unsigned long addr, int page_nid, int *flags);
673 
674 #endif	/* __MM_INTERNAL_H */
675