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b20a3503 | 1 | /* |
14e0f9bc | 2 | * Memory Migration functionality - linux/mm/migrate.c |
b20a3503 CL |
3 | * |
4 | * Copyright (C) 2006 Silicon Graphics, Inc., Christoph Lameter | |
5 | * | |
6 | * Page migration was first developed in the context of the memory hotplug | |
7 | * project. The main authors of the migration code are: | |
8 | * | |
9 | * IWAMOTO Toshihiro <iwamoto@valinux.co.jp> | |
10 | * Hirokazu Takahashi <taka@valinux.co.jp> | |
11 | * Dave Hansen <haveblue@us.ibm.com> | |
cde53535 | 12 | * Christoph Lameter |
b20a3503 CL |
13 | */ |
14 | ||
15 | #include <linux/migrate.h> | |
b95f1b31 | 16 | #include <linux/export.h> |
b20a3503 | 17 | #include <linux/swap.h> |
0697212a | 18 | #include <linux/swapops.h> |
b20a3503 | 19 | #include <linux/pagemap.h> |
e23ca00b | 20 | #include <linux/buffer_head.h> |
b20a3503 | 21 | #include <linux/mm_inline.h> |
b488893a | 22 | #include <linux/nsproxy.h> |
b20a3503 | 23 | #include <linux/pagevec.h> |
e9995ef9 | 24 | #include <linux/ksm.h> |
b20a3503 CL |
25 | #include <linux/rmap.h> |
26 | #include <linux/topology.h> | |
27 | #include <linux/cpu.h> | |
28 | #include <linux/cpuset.h> | |
04e62a29 | 29 | #include <linux/writeback.h> |
742755a1 CL |
30 | #include <linux/mempolicy.h> |
31 | #include <linux/vmalloc.h> | |
86c3a764 | 32 | #include <linux/security.h> |
42cb14b1 | 33 | #include <linux/backing-dev.h> |
bda807d4 | 34 | #include <linux/compaction.h> |
4f5ca265 | 35 | #include <linux/syscalls.h> |
290408d4 | 36 | #include <linux/hugetlb.h> |
8e6ac7fa | 37 | #include <linux/hugetlb_cgroup.h> |
5a0e3ad6 | 38 | #include <linux/gfp.h> |
bf6bddf1 | 39 | #include <linux/balloon_compaction.h> |
f714f4f2 | 40 | #include <linux/mmu_notifier.h> |
33c3fc71 | 41 | #include <linux/page_idle.h> |
d435edca | 42 | #include <linux/page_owner.h> |
b20a3503 | 43 | |
0d1836c3 MN |
44 | #include <asm/tlbflush.h> |
45 | ||
7b2a2d4a MG |
46 | #define CREATE_TRACE_POINTS |
47 | #include <trace/events/migrate.h> | |
48 | ||
b20a3503 CL |
49 | #include "internal.h" |
50 | ||
b20a3503 | 51 | /* |
742755a1 | 52 | * migrate_prep() needs to be called before we start compiling a list of pages |
748446bb MG |
53 | * to be migrated using isolate_lru_page(). If scheduling work on other CPUs is |
54 | * undesirable, use migrate_prep_local() | |
b20a3503 CL |
55 | */ |
56 | int migrate_prep(void) | |
57 | { | |
b20a3503 CL |
58 | /* |
59 | * Clear the LRU lists so pages can be isolated. | |
60 | * Note that pages may be moved off the LRU after we have | |
61 | * drained them. Those pages will fail to migrate like other | |
62 | * pages that may be busy. | |
63 | */ | |
64 | lru_add_drain_all(); | |
65 | ||
66 | return 0; | |
67 | } | |
68 | ||
748446bb MG |
69 | /* Do the necessary work of migrate_prep but not if it involves other CPUs */ |
70 | int migrate_prep_local(void) | |
71 | { | |
72 | lru_add_drain(); | |
73 | ||
74 | return 0; | |
75 | } | |
76 | ||
9e5bcd61 | 77 | int isolate_movable_page(struct page *page, isolate_mode_t mode) |
bda807d4 MK |
78 | { |
79 | struct address_space *mapping; | |
80 | ||
81 | /* | |
82 | * Avoid burning cycles with pages that are yet under __free_pages(), | |
83 | * or just got freed under us. | |
84 | * | |
85 | * In case we 'win' a race for a movable page being freed under us and | |
86 | * raise its refcount preventing __free_pages() from doing its job | |
87 | * the put_page() at the end of this block will take care of | |
88 | * release this page, thus avoiding a nasty leakage. | |
89 | */ | |
90 | if (unlikely(!get_page_unless_zero(page))) | |
91 | goto out; | |
92 | ||
93 | /* | |
94 | * Check PageMovable before holding a PG_lock because page's owner | |
95 | * assumes anybody doesn't touch PG_lock of newly allocated page | |
96 | * so unconditionally grapping the lock ruins page's owner side. | |
97 | */ | |
98 | if (unlikely(!__PageMovable(page))) | |
99 | goto out_putpage; | |
100 | /* | |
101 | * As movable pages are not isolated from LRU lists, concurrent | |
102 | * compaction threads can race against page migration functions | |
103 | * as well as race against the releasing a page. | |
104 | * | |
105 | * In order to avoid having an already isolated movable page | |
106 | * being (wrongly) re-isolated while it is under migration, | |
107 | * or to avoid attempting to isolate pages being released, | |
108 | * lets be sure we have the page lock | |
109 | * before proceeding with the movable page isolation steps. | |
110 | */ | |
111 | if (unlikely(!trylock_page(page))) | |
112 | goto out_putpage; | |
113 | ||
114 | if (!PageMovable(page) || PageIsolated(page)) | |
115 | goto out_no_isolated; | |
116 | ||
117 | mapping = page_mapping(page); | |
118 | VM_BUG_ON_PAGE(!mapping, page); | |
119 | ||
120 | if (!mapping->a_ops->isolate_page(page, mode)) | |
121 | goto out_no_isolated; | |
122 | ||
123 | /* Driver shouldn't use PG_isolated bit of page->flags */ | |
124 | WARN_ON_ONCE(PageIsolated(page)); | |
125 | __SetPageIsolated(page); | |
126 | unlock_page(page); | |
127 | ||
9e5bcd61 | 128 | return 0; |
bda807d4 MK |
129 | |
130 | out_no_isolated: | |
131 | unlock_page(page); | |
132 | out_putpage: | |
133 | put_page(page); | |
134 | out: | |
9e5bcd61 | 135 | return -EBUSY; |
bda807d4 MK |
136 | } |
137 | ||
138 | /* It should be called on page which is PG_movable */ | |
139 | void putback_movable_page(struct page *page) | |
140 | { | |
141 | struct address_space *mapping; | |
142 | ||
143 | VM_BUG_ON_PAGE(!PageLocked(page), page); | |
144 | VM_BUG_ON_PAGE(!PageMovable(page), page); | |
145 | VM_BUG_ON_PAGE(!PageIsolated(page), page); | |
146 | ||
147 | mapping = page_mapping(page); | |
148 | mapping->a_ops->putback_page(page); | |
149 | __ClearPageIsolated(page); | |
150 | } | |
151 | ||
5733c7d1 RA |
152 | /* |
153 | * Put previously isolated pages back onto the appropriate lists | |
154 | * from where they were once taken off for compaction/migration. | |
155 | * | |
59c82b70 JK |
156 | * This function shall be used whenever the isolated pageset has been |
157 | * built from lru, balloon, hugetlbfs page. See isolate_migratepages_range() | |
158 | * and isolate_huge_page(). | |
5733c7d1 RA |
159 | */ |
160 | void putback_movable_pages(struct list_head *l) | |
161 | { | |
162 | struct page *page; | |
163 | struct page *page2; | |
164 | ||
b20a3503 | 165 | list_for_each_entry_safe(page, page2, l, lru) { |
31caf665 NH |
166 | if (unlikely(PageHuge(page))) { |
167 | putback_active_hugepage(page); | |
168 | continue; | |
169 | } | |
e24f0b8f | 170 | list_del(&page->lru); |
bda807d4 MK |
171 | /* |
172 | * We isolated non-lru movable page so here we can use | |
173 | * __PageMovable because LRU page's mapping cannot have | |
174 | * PAGE_MAPPING_MOVABLE. | |
175 | */ | |
b1123ea6 | 176 | if (unlikely(__PageMovable(page))) { |
bda807d4 MK |
177 | VM_BUG_ON_PAGE(!PageIsolated(page), page); |
178 | lock_page(page); | |
179 | if (PageMovable(page)) | |
180 | putback_movable_page(page); | |
181 | else | |
182 | __ClearPageIsolated(page); | |
183 | unlock_page(page); | |
184 | put_page(page); | |
185 | } else { | |
bf6bddf1 | 186 | putback_lru_page(page); |
6afcf8ef ML |
187 | dec_node_page_state(page, NR_ISOLATED_ANON + |
188 | page_is_file_cache(page)); | |
bda807d4 | 189 | } |
b20a3503 | 190 | } |
b20a3503 CL |
191 | } |
192 | ||
0697212a CL |
193 | /* |
194 | * Restore a potential migration pte to a working pte entry | |
195 | */ | |
3fe87967 | 196 | static int remove_migration_pte(struct page *page, struct vm_area_struct *vma, |
e9995ef9 | 197 | unsigned long addr, void *old) |
0697212a | 198 | { |
3fe87967 KS |
199 | struct page_vma_mapped_walk pvmw = { |
200 | .page = old, | |
201 | .vma = vma, | |
202 | .address = addr, | |
203 | .flags = PVMW_SYNC | PVMW_MIGRATION, | |
204 | }; | |
205 | struct page *new; | |
206 | pte_t pte; | |
0697212a | 207 | swp_entry_t entry; |
0697212a | 208 | |
3fe87967 KS |
209 | VM_BUG_ON_PAGE(PageTail(page), page); |
210 | while (page_vma_mapped_walk(&pvmw)) { | |
211 | new = page - pvmw.page->index + | |
212 | linear_page_index(vma, pvmw.address); | |
0697212a | 213 | |
3fe87967 KS |
214 | get_page(new); |
215 | pte = pte_mkold(mk_pte(new, READ_ONCE(vma->vm_page_prot))); | |
216 | if (pte_swp_soft_dirty(*pvmw.pte)) | |
217 | pte = pte_mksoft_dirty(pte); | |
0697212a | 218 | |
3fe87967 KS |
219 | /* |
220 | * Recheck VMA as permissions can change since migration started | |
221 | */ | |
222 | entry = pte_to_swp_entry(*pvmw.pte); | |
223 | if (is_write_migration_entry(entry)) | |
224 | pte = maybe_mkwrite(pte, vma); | |
d3cb8bf6 | 225 | |
3ef8fd7f | 226 | #ifdef CONFIG_HUGETLB_PAGE |
3fe87967 KS |
227 | if (PageHuge(new)) { |
228 | pte = pte_mkhuge(pte); | |
229 | pte = arch_make_huge_pte(pte, vma, new, 0); | |
230 | } | |
3ef8fd7f | 231 | #endif |
3fe87967 KS |
232 | flush_dcache_page(new); |
233 | set_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte); | |
04e62a29 | 234 | |
3fe87967 KS |
235 | if (PageHuge(new)) { |
236 | if (PageAnon(new)) | |
237 | hugepage_add_anon_rmap(new, vma, pvmw.address); | |
238 | else | |
239 | page_dup_rmap(new, true); | |
240 | } else if (PageAnon(new)) | |
241 | page_add_anon_rmap(new, vma, pvmw.address, false); | |
290408d4 | 242 | else |
3fe87967 | 243 | page_add_file_rmap(new, false); |
04e62a29 | 244 | |
3fe87967 KS |
245 | if (vma->vm_flags & VM_LOCKED && !PageTransCompound(new)) |
246 | mlock_vma_page(new); | |
247 | ||
248 | /* No need to invalidate - it was non-present before */ | |
249 | update_mmu_cache(vma, pvmw.address, pvmw.pte); | |
250 | } | |
51afb12b | 251 | |
e9995ef9 | 252 | return SWAP_AGAIN; |
0697212a CL |
253 | } |
254 | ||
04e62a29 CL |
255 | /* |
256 | * Get rid of all migration entries and replace them by | |
257 | * references to the indicated page. | |
258 | */ | |
e388466d | 259 | void remove_migration_ptes(struct page *old, struct page *new, bool locked) |
04e62a29 | 260 | { |
051ac83a JK |
261 | struct rmap_walk_control rwc = { |
262 | .rmap_one = remove_migration_pte, | |
263 | .arg = old, | |
264 | }; | |
265 | ||
e388466d KS |
266 | if (locked) |
267 | rmap_walk_locked(new, &rwc); | |
268 | else | |
269 | rmap_walk(new, &rwc); | |
04e62a29 CL |
270 | } |
271 | ||
0697212a CL |
272 | /* |
273 | * Something used the pte of a page under migration. We need to | |
274 | * get to the page and wait until migration is finished. | |
275 | * When we return from this function the fault will be retried. | |
0697212a | 276 | */ |
e66f17ff | 277 | void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, |
30dad309 | 278 | spinlock_t *ptl) |
0697212a | 279 | { |
30dad309 | 280 | pte_t pte; |
0697212a CL |
281 | swp_entry_t entry; |
282 | struct page *page; | |
283 | ||
30dad309 | 284 | spin_lock(ptl); |
0697212a CL |
285 | pte = *ptep; |
286 | if (!is_swap_pte(pte)) | |
287 | goto out; | |
288 | ||
289 | entry = pte_to_swp_entry(pte); | |
290 | if (!is_migration_entry(entry)) | |
291 | goto out; | |
292 | ||
293 | page = migration_entry_to_page(entry); | |
294 | ||
e286781d NP |
295 | /* |
296 | * Once radix-tree replacement of page migration started, page_count | |
297 | * *must* be zero. And, we don't want to call wait_on_page_locked() | |
298 | * against a page without get_page(). | |
299 | * So, we use get_page_unless_zero(), here. Even failed, page fault | |
300 | * will occur again. | |
301 | */ | |
302 | if (!get_page_unless_zero(page)) | |
303 | goto out; | |
0697212a CL |
304 | pte_unmap_unlock(ptep, ptl); |
305 | wait_on_page_locked(page); | |
306 | put_page(page); | |
307 | return; | |
308 | out: | |
309 | pte_unmap_unlock(ptep, ptl); | |
310 | } | |
311 | ||
30dad309 NH |
312 | void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, |
313 | unsigned long address) | |
314 | { | |
315 | spinlock_t *ptl = pte_lockptr(mm, pmd); | |
316 | pte_t *ptep = pte_offset_map(pmd, address); | |
317 | __migration_entry_wait(mm, ptep, ptl); | |
318 | } | |
319 | ||
cb900f41 KS |
320 | void migration_entry_wait_huge(struct vm_area_struct *vma, |
321 | struct mm_struct *mm, pte_t *pte) | |
30dad309 | 322 | { |
cb900f41 | 323 | spinlock_t *ptl = huge_pte_lockptr(hstate_vma(vma), mm, pte); |
30dad309 NH |
324 | __migration_entry_wait(mm, pte, ptl); |
325 | } | |
326 | ||
b969c4ab MG |
327 | #ifdef CONFIG_BLOCK |
328 | /* Returns true if all buffers are successfully locked */ | |
a6bc32b8 MG |
329 | static bool buffer_migrate_lock_buffers(struct buffer_head *head, |
330 | enum migrate_mode mode) | |
b969c4ab MG |
331 | { |
332 | struct buffer_head *bh = head; | |
333 | ||
334 | /* Simple case, sync compaction */ | |
a6bc32b8 | 335 | if (mode != MIGRATE_ASYNC) { |
b969c4ab MG |
336 | do { |
337 | get_bh(bh); | |
338 | lock_buffer(bh); | |
339 | bh = bh->b_this_page; | |
340 | ||
341 | } while (bh != head); | |
342 | ||
343 | return true; | |
344 | } | |
345 | ||
346 | /* async case, we cannot block on lock_buffer so use trylock_buffer */ | |
347 | do { | |
348 | get_bh(bh); | |
349 | if (!trylock_buffer(bh)) { | |
350 | /* | |
351 | * We failed to lock the buffer and cannot stall in | |
352 | * async migration. Release the taken locks | |
353 | */ | |
354 | struct buffer_head *failed_bh = bh; | |
355 | put_bh(failed_bh); | |
356 | bh = head; | |
357 | while (bh != failed_bh) { | |
358 | unlock_buffer(bh); | |
359 | put_bh(bh); | |
360 | bh = bh->b_this_page; | |
361 | } | |
362 | return false; | |
363 | } | |
364 | ||
365 | bh = bh->b_this_page; | |
366 | } while (bh != head); | |
367 | return true; | |
368 | } | |
369 | #else | |
370 | static inline bool buffer_migrate_lock_buffers(struct buffer_head *head, | |
a6bc32b8 | 371 | enum migrate_mode mode) |
b969c4ab MG |
372 | { |
373 | return true; | |
374 | } | |
375 | #endif /* CONFIG_BLOCK */ | |
376 | ||
b20a3503 | 377 | /* |
c3fcf8a5 | 378 | * Replace the page in the mapping. |
5b5c7120 CL |
379 | * |
380 | * The number of remaining references must be: | |
381 | * 1 for anonymous pages without a mapping | |
382 | * 2 for pages with a mapping | |
266cf658 | 383 | * 3 for pages with a mapping and PagePrivate/PagePrivate2 set. |
b20a3503 | 384 | */ |
36bc08cc | 385 | int migrate_page_move_mapping(struct address_space *mapping, |
b969c4ab | 386 | struct page *newpage, struct page *page, |
8e321fef BL |
387 | struct buffer_head *head, enum migrate_mode mode, |
388 | int extra_count) | |
b20a3503 | 389 | { |
42cb14b1 HD |
390 | struct zone *oldzone, *newzone; |
391 | int dirty; | |
8e321fef | 392 | int expected_count = 1 + extra_count; |
7cf9c2c7 | 393 | void **pslot; |
b20a3503 | 394 | |
6c5240ae | 395 | if (!mapping) { |
0e8c7d0f | 396 | /* Anonymous page without mapping */ |
8e321fef | 397 | if (page_count(page) != expected_count) |
6c5240ae | 398 | return -EAGAIN; |
cf4b769a HD |
399 | |
400 | /* No turning back from here */ | |
cf4b769a HD |
401 | newpage->index = page->index; |
402 | newpage->mapping = page->mapping; | |
403 | if (PageSwapBacked(page)) | |
fa9949da | 404 | __SetPageSwapBacked(newpage); |
cf4b769a | 405 | |
78bd5209 | 406 | return MIGRATEPAGE_SUCCESS; |
6c5240ae CL |
407 | } |
408 | ||
42cb14b1 HD |
409 | oldzone = page_zone(page); |
410 | newzone = page_zone(newpage); | |
411 | ||
19fd6231 | 412 | spin_lock_irq(&mapping->tree_lock); |
b20a3503 | 413 | |
7cf9c2c7 NP |
414 | pslot = radix_tree_lookup_slot(&mapping->page_tree, |
415 | page_index(page)); | |
b20a3503 | 416 | |
8e321fef | 417 | expected_count += 1 + page_has_private(page); |
e286781d | 418 | if (page_count(page) != expected_count || |
29c1f677 | 419 | radix_tree_deref_slot_protected(pslot, &mapping->tree_lock) != page) { |
19fd6231 | 420 | spin_unlock_irq(&mapping->tree_lock); |
e23ca00b | 421 | return -EAGAIN; |
b20a3503 CL |
422 | } |
423 | ||
fe896d18 | 424 | if (!page_ref_freeze(page, expected_count)) { |
19fd6231 | 425 | spin_unlock_irq(&mapping->tree_lock); |
e286781d NP |
426 | return -EAGAIN; |
427 | } | |
428 | ||
b969c4ab MG |
429 | /* |
430 | * In the async migration case of moving a page with buffers, lock the | |
431 | * buffers using trylock before the mapping is moved. If the mapping | |
432 | * was moved, we later failed to lock the buffers and could not move | |
433 | * the mapping back due to an elevated page count, we would have to | |
434 | * block waiting on other references to be dropped. | |
435 | */ | |
a6bc32b8 MG |
436 | if (mode == MIGRATE_ASYNC && head && |
437 | !buffer_migrate_lock_buffers(head, mode)) { | |
fe896d18 | 438 | page_ref_unfreeze(page, expected_count); |
b969c4ab MG |
439 | spin_unlock_irq(&mapping->tree_lock); |
440 | return -EAGAIN; | |
441 | } | |
442 | ||
b20a3503 | 443 | /* |
cf4b769a HD |
444 | * Now we know that no one else is looking at the page: |
445 | * no turning back from here. | |
b20a3503 | 446 | */ |
cf4b769a HD |
447 | newpage->index = page->index; |
448 | newpage->mapping = page->mapping; | |
7cf9c2c7 | 449 | get_page(newpage); /* add cache reference */ |
6326fec1 NP |
450 | if (PageSwapBacked(page)) { |
451 | __SetPageSwapBacked(newpage); | |
452 | if (PageSwapCache(page)) { | |
453 | SetPageSwapCache(newpage); | |
454 | set_page_private(newpage, page_private(page)); | |
455 | } | |
456 | } else { | |
457 | VM_BUG_ON_PAGE(PageSwapCache(page), page); | |
b20a3503 CL |
458 | } |
459 | ||
42cb14b1 HD |
460 | /* Move dirty while page refs frozen and newpage not yet exposed */ |
461 | dirty = PageDirty(page); | |
462 | if (dirty) { | |
463 | ClearPageDirty(page); | |
464 | SetPageDirty(newpage); | |
465 | } | |
466 | ||
6d75f366 | 467 | radix_tree_replace_slot(&mapping->page_tree, pslot, newpage); |
7cf9c2c7 NP |
468 | |
469 | /* | |
937a94c9 JG |
470 | * Drop cache reference from old page by unfreezing |
471 | * to one less reference. | |
7cf9c2c7 NP |
472 | * We know this isn't the last reference. |
473 | */ | |
fe896d18 | 474 | page_ref_unfreeze(page, expected_count - 1); |
7cf9c2c7 | 475 | |
42cb14b1 HD |
476 | spin_unlock(&mapping->tree_lock); |
477 | /* Leave irq disabled to prevent preemption while updating stats */ | |
478 | ||
0e8c7d0f CL |
479 | /* |
480 | * If moved to a different zone then also account | |
481 | * the page for that zone. Other VM counters will be | |
482 | * taken care of when we establish references to the | |
483 | * new page and drop references to the old page. | |
484 | * | |
485 | * Note that anonymous pages are accounted for | |
4b9d0fab | 486 | * via NR_FILE_PAGES and NR_ANON_MAPPED if they |
0e8c7d0f CL |
487 | * are mapped to swap space. |
488 | */ | |
42cb14b1 | 489 | if (newzone != oldzone) { |
11fb9989 MG |
490 | __dec_node_state(oldzone->zone_pgdat, NR_FILE_PAGES); |
491 | __inc_node_state(newzone->zone_pgdat, NR_FILE_PAGES); | |
42cb14b1 | 492 | if (PageSwapBacked(page) && !PageSwapCache(page)) { |
11fb9989 MG |
493 | __dec_node_state(oldzone->zone_pgdat, NR_SHMEM); |
494 | __inc_node_state(newzone->zone_pgdat, NR_SHMEM); | |
42cb14b1 HD |
495 | } |
496 | if (dirty && mapping_cap_account_dirty(mapping)) { | |
11fb9989 | 497 | __dec_node_state(oldzone->zone_pgdat, NR_FILE_DIRTY); |
5a1c84b4 | 498 | __dec_zone_state(oldzone, NR_ZONE_WRITE_PENDING); |
11fb9989 | 499 | __inc_node_state(newzone->zone_pgdat, NR_FILE_DIRTY); |
5a1c84b4 | 500 | __inc_zone_state(newzone, NR_ZONE_WRITE_PENDING); |
42cb14b1 | 501 | } |
4b02108a | 502 | } |
42cb14b1 | 503 | local_irq_enable(); |
b20a3503 | 504 | |
78bd5209 | 505 | return MIGRATEPAGE_SUCCESS; |
b20a3503 | 506 | } |
1118dce7 | 507 | EXPORT_SYMBOL(migrate_page_move_mapping); |
b20a3503 | 508 | |
290408d4 NH |
509 | /* |
510 | * The expected number of remaining references is the same as that | |
511 | * of migrate_page_move_mapping(). | |
512 | */ | |
513 | int migrate_huge_page_move_mapping(struct address_space *mapping, | |
514 | struct page *newpage, struct page *page) | |
515 | { | |
516 | int expected_count; | |
517 | void **pslot; | |
518 | ||
290408d4 NH |
519 | spin_lock_irq(&mapping->tree_lock); |
520 | ||
521 | pslot = radix_tree_lookup_slot(&mapping->page_tree, | |
522 | page_index(page)); | |
523 | ||
524 | expected_count = 2 + page_has_private(page); | |
525 | if (page_count(page) != expected_count || | |
29c1f677 | 526 | radix_tree_deref_slot_protected(pslot, &mapping->tree_lock) != page) { |
290408d4 NH |
527 | spin_unlock_irq(&mapping->tree_lock); |
528 | return -EAGAIN; | |
529 | } | |
530 | ||
fe896d18 | 531 | if (!page_ref_freeze(page, expected_count)) { |
290408d4 NH |
532 | spin_unlock_irq(&mapping->tree_lock); |
533 | return -EAGAIN; | |
534 | } | |
535 | ||
cf4b769a HD |
536 | newpage->index = page->index; |
537 | newpage->mapping = page->mapping; | |
6a93ca8f | 538 | |
290408d4 NH |
539 | get_page(newpage); |
540 | ||
6d75f366 | 541 | radix_tree_replace_slot(&mapping->page_tree, pslot, newpage); |
290408d4 | 542 | |
fe896d18 | 543 | page_ref_unfreeze(page, expected_count - 1); |
290408d4 NH |
544 | |
545 | spin_unlock_irq(&mapping->tree_lock); | |
6a93ca8f | 546 | |
78bd5209 | 547 | return MIGRATEPAGE_SUCCESS; |
290408d4 NH |
548 | } |
549 | ||
30b0a105 DH |
550 | /* |
551 | * Gigantic pages are so large that we do not guarantee that page++ pointer | |
552 | * arithmetic will work across the entire page. We need something more | |
553 | * specialized. | |
554 | */ | |
555 | static void __copy_gigantic_page(struct page *dst, struct page *src, | |
556 | int nr_pages) | |
557 | { | |
558 | int i; | |
559 | struct page *dst_base = dst; | |
560 | struct page *src_base = src; | |
561 | ||
562 | for (i = 0; i < nr_pages; ) { | |
563 | cond_resched(); | |
564 | copy_highpage(dst, src); | |
565 | ||
566 | i++; | |
567 | dst = mem_map_next(dst, dst_base, i); | |
568 | src = mem_map_next(src, src_base, i); | |
569 | } | |
570 | } | |
571 | ||
572 | static void copy_huge_page(struct page *dst, struct page *src) | |
573 | { | |
574 | int i; | |
575 | int nr_pages; | |
576 | ||
577 | if (PageHuge(src)) { | |
578 | /* hugetlbfs page */ | |
579 | struct hstate *h = page_hstate(src); | |
580 | nr_pages = pages_per_huge_page(h); | |
581 | ||
582 | if (unlikely(nr_pages > MAX_ORDER_NR_PAGES)) { | |
583 | __copy_gigantic_page(dst, src, nr_pages); | |
584 | return; | |
585 | } | |
586 | } else { | |
587 | /* thp page */ | |
588 | BUG_ON(!PageTransHuge(src)); | |
589 | nr_pages = hpage_nr_pages(src); | |
590 | } | |
591 | ||
592 | for (i = 0; i < nr_pages; i++) { | |
593 | cond_resched(); | |
594 | copy_highpage(dst + i, src + i); | |
595 | } | |
596 | } | |
597 | ||
b20a3503 CL |
598 | /* |
599 | * Copy the page to its new location | |
600 | */ | |
290408d4 | 601 | void migrate_page_copy(struct page *newpage, struct page *page) |
b20a3503 | 602 | { |
7851a45c RR |
603 | int cpupid; |
604 | ||
b32967ff | 605 | if (PageHuge(page) || PageTransHuge(page)) |
290408d4 NH |
606 | copy_huge_page(newpage, page); |
607 | else | |
608 | copy_highpage(newpage, page); | |
b20a3503 CL |
609 | |
610 | if (PageError(page)) | |
611 | SetPageError(newpage); | |
612 | if (PageReferenced(page)) | |
613 | SetPageReferenced(newpage); | |
614 | if (PageUptodate(page)) | |
615 | SetPageUptodate(newpage); | |
894bc310 | 616 | if (TestClearPageActive(page)) { |
309381fe | 617 | VM_BUG_ON_PAGE(PageUnevictable(page), page); |
b20a3503 | 618 | SetPageActive(newpage); |
418b27ef LS |
619 | } else if (TestClearPageUnevictable(page)) |
620 | SetPageUnevictable(newpage); | |
b20a3503 CL |
621 | if (PageChecked(page)) |
622 | SetPageChecked(newpage); | |
623 | if (PageMappedToDisk(page)) | |
624 | SetPageMappedToDisk(newpage); | |
625 | ||
42cb14b1 HD |
626 | /* Move dirty on pages not done by migrate_page_move_mapping() */ |
627 | if (PageDirty(page)) | |
628 | SetPageDirty(newpage); | |
b20a3503 | 629 | |
33c3fc71 VD |
630 | if (page_is_young(page)) |
631 | set_page_young(newpage); | |
632 | if (page_is_idle(page)) | |
633 | set_page_idle(newpage); | |
634 | ||
7851a45c RR |
635 | /* |
636 | * Copy NUMA information to the new page, to prevent over-eager | |
637 | * future migrations of this same page. | |
638 | */ | |
639 | cpupid = page_cpupid_xchg_last(page, -1); | |
640 | page_cpupid_xchg_last(newpage, cpupid); | |
641 | ||
e9995ef9 | 642 | ksm_migrate_page(newpage, page); |
c8d6553b HD |
643 | /* |
644 | * Please do not reorder this without considering how mm/ksm.c's | |
645 | * get_ksm_page() depends upon ksm_migrate_page() and PageSwapCache(). | |
646 | */ | |
b3b3a99c NH |
647 | if (PageSwapCache(page)) |
648 | ClearPageSwapCache(page); | |
b20a3503 CL |
649 | ClearPagePrivate(page); |
650 | set_page_private(page, 0); | |
b20a3503 CL |
651 | |
652 | /* | |
653 | * If any waiters have accumulated on the new page then | |
654 | * wake them up. | |
655 | */ | |
656 | if (PageWriteback(newpage)) | |
657 | end_page_writeback(newpage); | |
d435edca VB |
658 | |
659 | copy_page_owner(page, newpage); | |
74485cf2 JW |
660 | |
661 | mem_cgroup_migrate(page, newpage); | |
b20a3503 | 662 | } |
1118dce7 | 663 | EXPORT_SYMBOL(migrate_page_copy); |
b20a3503 | 664 | |
1d8b85cc CL |
665 | /************************************************************ |
666 | * Migration functions | |
667 | ***********************************************************/ | |
668 | ||
b20a3503 | 669 | /* |
bda807d4 | 670 | * Common logic to directly migrate a single LRU page suitable for |
266cf658 | 671 | * pages that do not use PagePrivate/PagePrivate2. |
b20a3503 CL |
672 | * |
673 | * Pages are locked upon entry and exit. | |
674 | */ | |
2d1db3b1 | 675 | int migrate_page(struct address_space *mapping, |
a6bc32b8 MG |
676 | struct page *newpage, struct page *page, |
677 | enum migrate_mode mode) | |
b20a3503 CL |
678 | { |
679 | int rc; | |
680 | ||
681 | BUG_ON(PageWriteback(page)); /* Writeback must be complete */ | |
682 | ||
8e321fef | 683 | rc = migrate_page_move_mapping(mapping, newpage, page, NULL, mode, 0); |
b20a3503 | 684 | |
78bd5209 | 685 | if (rc != MIGRATEPAGE_SUCCESS) |
b20a3503 CL |
686 | return rc; |
687 | ||
688 | migrate_page_copy(newpage, page); | |
78bd5209 | 689 | return MIGRATEPAGE_SUCCESS; |
b20a3503 CL |
690 | } |
691 | EXPORT_SYMBOL(migrate_page); | |
692 | ||
9361401e | 693 | #ifdef CONFIG_BLOCK |
1d8b85cc CL |
694 | /* |
695 | * Migration function for pages with buffers. This function can only be used | |
696 | * if the underlying filesystem guarantees that no other references to "page" | |
697 | * exist. | |
698 | */ | |
2d1db3b1 | 699 | int buffer_migrate_page(struct address_space *mapping, |
a6bc32b8 | 700 | struct page *newpage, struct page *page, enum migrate_mode mode) |
1d8b85cc | 701 | { |
1d8b85cc CL |
702 | struct buffer_head *bh, *head; |
703 | int rc; | |
704 | ||
1d8b85cc | 705 | if (!page_has_buffers(page)) |
a6bc32b8 | 706 | return migrate_page(mapping, newpage, page, mode); |
1d8b85cc CL |
707 | |
708 | head = page_buffers(page); | |
709 | ||
8e321fef | 710 | rc = migrate_page_move_mapping(mapping, newpage, page, head, mode, 0); |
1d8b85cc | 711 | |
78bd5209 | 712 | if (rc != MIGRATEPAGE_SUCCESS) |
1d8b85cc CL |
713 | return rc; |
714 | ||
b969c4ab MG |
715 | /* |
716 | * In the async case, migrate_page_move_mapping locked the buffers | |
717 | * with an IRQ-safe spinlock held. In the sync case, the buffers | |
718 | * need to be locked now | |
719 | */ | |
a6bc32b8 MG |
720 | if (mode != MIGRATE_ASYNC) |
721 | BUG_ON(!buffer_migrate_lock_buffers(head, mode)); | |
1d8b85cc CL |
722 | |
723 | ClearPagePrivate(page); | |
724 | set_page_private(newpage, page_private(page)); | |
725 | set_page_private(page, 0); | |
726 | put_page(page); | |
727 | get_page(newpage); | |
728 | ||
729 | bh = head; | |
730 | do { | |
731 | set_bh_page(bh, newpage, bh_offset(bh)); | |
732 | bh = bh->b_this_page; | |
733 | ||
734 | } while (bh != head); | |
735 | ||
736 | SetPagePrivate(newpage); | |
737 | ||
738 | migrate_page_copy(newpage, page); | |
739 | ||
740 | bh = head; | |
741 | do { | |
742 | unlock_buffer(bh); | |
743 | put_bh(bh); | |
744 | bh = bh->b_this_page; | |
745 | ||
746 | } while (bh != head); | |
747 | ||
78bd5209 | 748 | return MIGRATEPAGE_SUCCESS; |
1d8b85cc CL |
749 | } |
750 | EXPORT_SYMBOL(buffer_migrate_page); | |
9361401e | 751 | #endif |
1d8b85cc | 752 | |
04e62a29 CL |
753 | /* |
754 | * Writeback a page to clean the dirty state | |
755 | */ | |
756 | static int writeout(struct address_space *mapping, struct page *page) | |
8351a6e4 | 757 | { |
04e62a29 CL |
758 | struct writeback_control wbc = { |
759 | .sync_mode = WB_SYNC_NONE, | |
760 | .nr_to_write = 1, | |
761 | .range_start = 0, | |
762 | .range_end = LLONG_MAX, | |
04e62a29 CL |
763 | .for_reclaim = 1 |
764 | }; | |
765 | int rc; | |
766 | ||
767 | if (!mapping->a_ops->writepage) | |
768 | /* No write method for the address space */ | |
769 | return -EINVAL; | |
770 | ||
771 | if (!clear_page_dirty_for_io(page)) | |
772 | /* Someone else already triggered a write */ | |
773 | return -EAGAIN; | |
774 | ||
8351a6e4 | 775 | /* |
04e62a29 CL |
776 | * A dirty page may imply that the underlying filesystem has |
777 | * the page on some queue. So the page must be clean for | |
778 | * migration. Writeout may mean we loose the lock and the | |
779 | * page state is no longer what we checked for earlier. | |
780 | * At this point we know that the migration attempt cannot | |
781 | * be successful. | |
8351a6e4 | 782 | */ |
e388466d | 783 | remove_migration_ptes(page, page, false); |
8351a6e4 | 784 | |
04e62a29 | 785 | rc = mapping->a_ops->writepage(page, &wbc); |
8351a6e4 | 786 | |
04e62a29 CL |
787 | if (rc != AOP_WRITEPAGE_ACTIVATE) |
788 | /* unlocked. Relock */ | |
789 | lock_page(page); | |
790 | ||
bda8550d | 791 | return (rc < 0) ? -EIO : -EAGAIN; |
04e62a29 CL |
792 | } |
793 | ||
794 | /* | |
795 | * Default handling if a filesystem does not provide a migration function. | |
796 | */ | |
797 | static int fallback_migrate_page(struct address_space *mapping, | |
a6bc32b8 | 798 | struct page *newpage, struct page *page, enum migrate_mode mode) |
04e62a29 | 799 | { |
b969c4ab | 800 | if (PageDirty(page)) { |
a6bc32b8 MG |
801 | /* Only writeback pages in full synchronous migration */ |
802 | if (mode != MIGRATE_SYNC) | |
b969c4ab | 803 | return -EBUSY; |
04e62a29 | 804 | return writeout(mapping, page); |
b969c4ab | 805 | } |
8351a6e4 CL |
806 | |
807 | /* | |
808 | * Buffers may be managed in a filesystem specific way. | |
809 | * We must have no buffers or drop them. | |
810 | */ | |
266cf658 | 811 | if (page_has_private(page) && |
8351a6e4 CL |
812 | !try_to_release_page(page, GFP_KERNEL)) |
813 | return -EAGAIN; | |
814 | ||
a6bc32b8 | 815 | return migrate_page(mapping, newpage, page, mode); |
8351a6e4 CL |
816 | } |
817 | ||
e24f0b8f CL |
818 | /* |
819 | * Move a page to a newly allocated page | |
820 | * The page is locked and all ptes have been successfully removed. | |
821 | * | |
822 | * The new page will have replaced the old page if this function | |
823 | * is successful. | |
894bc310 LS |
824 | * |
825 | * Return value: | |
826 | * < 0 - error code | |
78bd5209 | 827 | * MIGRATEPAGE_SUCCESS - success |
e24f0b8f | 828 | */ |
3fe2011f | 829 | static int move_to_new_page(struct page *newpage, struct page *page, |
5c3f9a67 | 830 | enum migrate_mode mode) |
e24f0b8f CL |
831 | { |
832 | struct address_space *mapping; | |
bda807d4 MK |
833 | int rc = -EAGAIN; |
834 | bool is_lru = !__PageMovable(page); | |
e24f0b8f | 835 | |
7db7671f HD |
836 | VM_BUG_ON_PAGE(!PageLocked(page), page); |
837 | VM_BUG_ON_PAGE(!PageLocked(newpage), newpage); | |
e24f0b8f | 838 | |
e24f0b8f | 839 | mapping = page_mapping(page); |
bda807d4 MK |
840 | |
841 | if (likely(is_lru)) { | |
842 | if (!mapping) | |
843 | rc = migrate_page(mapping, newpage, page, mode); | |
844 | else if (mapping->a_ops->migratepage) | |
845 | /* | |
846 | * Most pages have a mapping and most filesystems | |
847 | * provide a migratepage callback. Anonymous pages | |
848 | * are part of swap space which also has its own | |
849 | * migratepage callback. This is the most common path | |
850 | * for page migration. | |
851 | */ | |
852 | rc = mapping->a_ops->migratepage(mapping, newpage, | |
853 | page, mode); | |
854 | else | |
855 | rc = fallback_migrate_page(mapping, newpage, | |
856 | page, mode); | |
857 | } else { | |
e24f0b8f | 858 | /* |
bda807d4 MK |
859 | * In case of non-lru page, it could be released after |
860 | * isolation step. In that case, we shouldn't try migration. | |
e24f0b8f | 861 | */ |
bda807d4 MK |
862 | VM_BUG_ON_PAGE(!PageIsolated(page), page); |
863 | if (!PageMovable(page)) { | |
864 | rc = MIGRATEPAGE_SUCCESS; | |
865 | __ClearPageIsolated(page); | |
866 | goto out; | |
867 | } | |
868 | ||
869 | rc = mapping->a_ops->migratepage(mapping, newpage, | |
870 | page, mode); | |
871 | WARN_ON_ONCE(rc == MIGRATEPAGE_SUCCESS && | |
872 | !PageIsolated(page)); | |
873 | } | |
e24f0b8f | 874 | |
5c3f9a67 HD |
875 | /* |
876 | * When successful, old pagecache page->mapping must be cleared before | |
877 | * page is freed; but stats require that PageAnon be left as PageAnon. | |
878 | */ | |
879 | if (rc == MIGRATEPAGE_SUCCESS) { | |
bda807d4 MK |
880 | if (__PageMovable(page)) { |
881 | VM_BUG_ON_PAGE(!PageIsolated(page), page); | |
882 | ||
883 | /* | |
884 | * We clear PG_movable under page_lock so any compactor | |
885 | * cannot try to migrate this page. | |
886 | */ | |
887 | __ClearPageIsolated(page); | |
888 | } | |
889 | ||
890 | /* | |
891 | * Anonymous and movable page->mapping will be cleard by | |
892 | * free_pages_prepare so don't reset it here for keeping | |
893 | * the type to work PageAnon, for example. | |
894 | */ | |
895 | if (!PageMappingFlags(page)) | |
5c3f9a67 | 896 | page->mapping = NULL; |
3fe2011f | 897 | } |
bda807d4 | 898 | out: |
e24f0b8f CL |
899 | return rc; |
900 | } | |
901 | ||
0dabec93 | 902 | static int __unmap_and_move(struct page *page, struct page *newpage, |
9c620e2b | 903 | int force, enum migrate_mode mode) |
e24f0b8f | 904 | { |
0dabec93 | 905 | int rc = -EAGAIN; |
2ebba6b7 | 906 | int page_was_mapped = 0; |
3f6c8272 | 907 | struct anon_vma *anon_vma = NULL; |
bda807d4 | 908 | bool is_lru = !__PageMovable(page); |
95a402c3 | 909 | |
529ae9aa | 910 | if (!trylock_page(page)) { |
a6bc32b8 | 911 | if (!force || mode == MIGRATE_ASYNC) |
0dabec93 | 912 | goto out; |
3e7d3449 MG |
913 | |
914 | /* | |
915 | * It's not safe for direct compaction to call lock_page. | |
916 | * For example, during page readahead pages are added locked | |
917 | * to the LRU. Later, when the IO completes the pages are | |
918 | * marked uptodate and unlocked. However, the queueing | |
919 | * could be merging multiple pages for one bio (e.g. | |
920 | * mpage_readpages). If an allocation happens for the | |
921 | * second or third page, the process can end up locking | |
922 | * the same page twice and deadlocking. Rather than | |
923 | * trying to be clever about what pages can be locked, | |
924 | * avoid the use of lock_page for direct compaction | |
925 | * altogether. | |
926 | */ | |
927 | if (current->flags & PF_MEMALLOC) | |
0dabec93 | 928 | goto out; |
3e7d3449 | 929 | |
e24f0b8f CL |
930 | lock_page(page); |
931 | } | |
932 | ||
933 | if (PageWriteback(page)) { | |
11bc82d6 | 934 | /* |
fed5b64a | 935 | * Only in the case of a full synchronous migration is it |
a6bc32b8 MG |
936 | * necessary to wait for PageWriteback. In the async case, |
937 | * the retry loop is too short and in the sync-light case, | |
938 | * the overhead of stalling is too much | |
11bc82d6 | 939 | */ |
a6bc32b8 | 940 | if (mode != MIGRATE_SYNC) { |
11bc82d6 | 941 | rc = -EBUSY; |
0a31bc97 | 942 | goto out_unlock; |
11bc82d6 AA |
943 | } |
944 | if (!force) | |
0a31bc97 | 945 | goto out_unlock; |
e24f0b8f CL |
946 | wait_on_page_writeback(page); |
947 | } | |
03f15c86 | 948 | |
e24f0b8f | 949 | /* |
dc386d4d KH |
950 | * By try_to_unmap(), page->mapcount goes down to 0 here. In this case, |
951 | * we cannot notice that anon_vma is freed while we migrates a page. | |
1ce82b69 | 952 | * This get_anon_vma() delays freeing anon_vma pointer until the end |
dc386d4d | 953 | * of migration. File cache pages are no problem because of page_lock() |
989f89c5 KH |
954 | * File Caches may use write_page() or lock_page() in migration, then, |
955 | * just care Anon page here. | |
03f15c86 HD |
956 | * |
957 | * Only page_get_anon_vma() understands the subtleties of | |
958 | * getting a hold on an anon_vma from outside one of its mms. | |
959 | * But if we cannot get anon_vma, then we won't need it anyway, | |
960 | * because that implies that the anon page is no longer mapped | |
961 | * (and cannot be remapped so long as we hold the page lock). | |
dc386d4d | 962 | */ |
03f15c86 | 963 | if (PageAnon(page) && !PageKsm(page)) |
746b18d4 | 964 | anon_vma = page_get_anon_vma(page); |
62e1c553 | 965 | |
7db7671f HD |
966 | /* |
967 | * Block others from accessing the new page when we get around to | |
968 | * establishing additional references. We are usually the only one | |
969 | * holding a reference to newpage at this point. We used to have a BUG | |
970 | * here if trylock_page(newpage) fails, but would like to allow for | |
971 | * cases where there might be a race with the previous use of newpage. | |
972 | * This is much like races on refcount of oldpage: just don't BUG(). | |
973 | */ | |
974 | if (unlikely(!trylock_page(newpage))) | |
975 | goto out_unlock; | |
976 | ||
bda807d4 MK |
977 | if (unlikely(!is_lru)) { |
978 | rc = move_to_new_page(newpage, page, mode); | |
979 | goto out_unlock_both; | |
980 | } | |
981 | ||
dc386d4d | 982 | /* |
62e1c553 SL |
983 | * Corner case handling: |
984 | * 1. When a new swap-cache page is read into, it is added to the LRU | |
985 | * and treated as swapcache but it has no rmap yet. | |
986 | * Calling try_to_unmap() against a page->mapping==NULL page will | |
987 | * trigger a BUG. So handle it here. | |
988 | * 2. An orphaned page (see truncate_complete_page) might have | |
989 | * fs-private metadata. The page can be picked up due to memory | |
990 | * offlining. Everywhere else except page reclaim, the page is | |
991 | * invisible to the vm, so the page can not be migrated. So try to | |
992 | * free the metadata, so the page can be freed. | |
e24f0b8f | 993 | */ |
62e1c553 | 994 | if (!page->mapping) { |
309381fe | 995 | VM_BUG_ON_PAGE(PageAnon(page), page); |
1ce82b69 | 996 | if (page_has_private(page)) { |
62e1c553 | 997 | try_to_free_buffers(page); |
7db7671f | 998 | goto out_unlock_both; |
62e1c553 | 999 | } |
7db7671f HD |
1000 | } else if (page_mapped(page)) { |
1001 | /* Establish migration ptes */ | |
03f15c86 HD |
1002 | VM_BUG_ON_PAGE(PageAnon(page) && !PageKsm(page) && !anon_vma, |
1003 | page); | |
2ebba6b7 | 1004 | try_to_unmap(page, |
da1b13cc | 1005 | TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS); |
2ebba6b7 HD |
1006 | page_was_mapped = 1; |
1007 | } | |
dc386d4d | 1008 | |
e6a1530d | 1009 | if (!page_mapped(page)) |
5c3f9a67 | 1010 | rc = move_to_new_page(newpage, page, mode); |
e24f0b8f | 1011 | |
5c3f9a67 HD |
1012 | if (page_was_mapped) |
1013 | remove_migration_ptes(page, | |
e388466d | 1014 | rc == MIGRATEPAGE_SUCCESS ? newpage : page, false); |
3f6c8272 | 1015 | |
7db7671f HD |
1016 | out_unlock_both: |
1017 | unlock_page(newpage); | |
1018 | out_unlock: | |
3f6c8272 | 1019 | /* Drop an anon_vma reference if we took one */ |
76545066 | 1020 | if (anon_vma) |
9e60109f | 1021 | put_anon_vma(anon_vma); |
e24f0b8f | 1022 | unlock_page(page); |
0dabec93 | 1023 | out: |
c6c919eb MK |
1024 | /* |
1025 | * If migration is successful, decrease refcount of the newpage | |
1026 | * which will not free the page because new page owner increased | |
1027 | * refcounter. As well, if it is LRU page, add the page to LRU | |
1028 | * list in here. | |
1029 | */ | |
1030 | if (rc == MIGRATEPAGE_SUCCESS) { | |
b1123ea6 | 1031 | if (unlikely(__PageMovable(newpage))) |
c6c919eb MK |
1032 | put_page(newpage); |
1033 | else | |
1034 | putback_lru_page(newpage); | |
1035 | } | |
1036 | ||
0dabec93 MK |
1037 | return rc; |
1038 | } | |
95a402c3 | 1039 | |
ef2a5153 GU |
1040 | /* |
1041 | * gcc 4.7 and 4.8 on arm get an ICEs when inlining unmap_and_move(). Work | |
1042 | * around it. | |
1043 | */ | |
1044 | #if (GCC_VERSION >= 40700 && GCC_VERSION < 40900) && defined(CONFIG_ARM) | |
1045 | #define ICE_noinline noinline | |
1046 | #else | |
1047 | #define ICE_noinline | |
1048 | #endif | |
1049 | ||
0dabec93 MK |
1050 | /* |
1051 | * Obtain the lock on page, remove all ptes and migrate the page | |
1052 | * to the newly allocated page in newpage. | |
1053 | */ | |
ef2a5153 GU |
1054 | static ICE_noinline int unmap_and_move(new_page_t get_new_page, |
1055 | free_page_t put_new_page, | |
1056 | unsigned long private, struct page *page, | |
add05cec NH |
1057 | int force, enum migrate_mode mode, |
1058 | enum migrate_reason reason) | |
0dabec93 | 1059 | { |
2def7424 | 1060 | int rc = MIGRATEPAGE_SUCCESS; |
0dabec93 | 1061 | int *result = NULL; |
2def7424 | 1062 | struct page *newpage; |
0dabec93 | 1063 | |
2def7424 | 1064 | newpage = get_new_page(page, private, &result); |
0dabec93 MK |
1065 | if (!newpage) |
1066 | return -ENOMEM; | |
1067 | ||
1068 | if (page_count(page) == 1) { | |
1069 | /* page was freed from under us. So we are done. */ | |
c6c919eb MK |
1070 | ClearPageActive(page); |
1071 | ClearPageUnevictable(page); | |
bda807d4 MK |
1072 | if (unlikely(__PageMovable(page))) { |
1073 | lock_page(page); | |
1074 | if (!PageMovable(page)) | |
1075 | __ClearPageIsolated(page); | |
1076 | unlock_page(page); | |
1077 | } | |
c6c919eb MK |
1078 | if (put_new_page) |
1079 | put_new_page(newpage, private); | |
1080 | else | |
1081 | put_page(newpage); | |
0dabec93 MK |
1082 | goto out; |
1083 | } | |
1084 | ||
4d2fa965 KS |
1085 | if (unlikely(PageTransHuge(page))) { |
1086 | lock_page(page); | |
1087 | rc = split_huge_page(page); | |
1088 | unlock_page(page); | |
1089 | if (rc) | |
0dabec93 | 1090 | goto out; |
4d2fa965 | 1091 | } |
0dabec93 | 1092 | |
9c620e2b | 1093 | rc = __unmap_and_move(page, newpage, force, mode); |
c6c919eb | 1094 | if (rc == MIGRATEPAGE_SUCCESS) |
7cd12b4a | 1095 | set_page_owner_migrate_reason(newpage, reason); |
bf6bddf1 | 1096 | |
0dabec93 | 1097 | out: |
e24f0b8f | 1098 | if (rc != -EAGAIN) { |
0dabec93 MK |
1099 | /* |
1100 | * A page that has been migrated has all references | |
1101 | * removed and will be freed. A page that has not been | |
1102 | * migrated will have kepts its references and be | |
1103 | * restored. | |
1104 | */ | |
1105 | list_del(&page->lru); | |
6afcf8ef ML |
1106 | |
1107 | /* | |
1108 | * Compaction can migrate also non-LRU pages which are | |
1109 | * not accounted to NR_ISOLATED_*. They can be recognized | |
1110 | * as __PageMovable | |
1111 | */ | |
1112 | if (likely(!__PageMovable(page))) | |
1113 | dec_node_page_state(page, NR_ISOLATED_ANON + | |
1114 | page_is_file_cache(page)); | |
c6c919eb MK |
1115 | } |
1116 | ||
1117 | /* | |
1118 | * If migration is successful, releases reference grabbed during | |
1119 | * isolation. Otherwise, restore the page to right list unless | |
1120 | * we want to retry. | |
1121 | */ | |
1122 | if (rc == MIGRATEPAGE_SUCCESS) { | |
1123 | put_page(page); | |
1124 | if (reason == MR_MEMORY_FAILURE) { | |
d7e69488 | 1125 | /* |
c6c919eb MK |
1126 | * Set PG_HWPoison on just freed page |
1127 | * intentionally. Although it's rather weird, | |
1128 | * it's how HWPoison flag works at the moment. | |
d7e69488 | 1129 | */ |
da1b13cc WL |
1130 | if (!test_set_page_hwpoison(page)) |
1131 | num_poisoned_pages_inc(); | |
c6c919eb MK |
1132 | } |
1133 | } else { | |
bda807d4 MK |
1134 | if (rc != -EAGAIN) { |
1135 | if (likely(!__PageMovable(page))) { | |
1136 | putback_lru_page(page); | |
1137 | goto put_new; | |
1138 | } | |
1139 | ||
1140 | lock_page(page); | |
1141 | if (PageMovable(page)) | |
1142 | putback_movable_page(page); | |
1143 | else | |
1144 | __ClearPageIsolated(page); | |
1145 | unlock_page(page); | |
1146 | put_page(page); | |
1147 | } | |
1148 | put_new: | |
c6c919eb MK |
1149 | if (put_new_page) |
1150 | put_new_page(newpage, private); | |
1151 | else | |
1152 | put_page(newpage); | |
e24f0b8f | 1153 | } |
68711a74 | 1154 | |
742755a1 CL |
1155 | if (result) { |
1156 | if (rc) | |
1157 | *result = rc; | |
1158 | else | |
1159 | *result = page_to_nid(newpage); | |
1160 | } | |
e24f0b8f CL |
1161 | return rc; |
1162 | } | |
1163 | ||
290408d4 NH |
1164 | /* |
1165 | * Counterpart of unmap_and_move_page() for hugepage migration. | |
1166 | * | |
1167 | * This function doesn't wait the completion of hugepage I/O | |
1168 | * because there is no race between I/O and migration for hugepage. | |
1169 | * Note that currently hugepage I/O occurs only in direct I/O | |
1170 | * where no lock is held and PG_writeback is irrelevant, | |
1171 | * and writeback status of all subpages are counted in the reference | |
1172 | * count of the head page (i.e. if all subpages of a 2MB hugepage are | |
1173 | * under direct I/O, the reference of the head page is 512 and a bit more.) | |
1174 | * This means that when we try to migrate hugepage whose subpages are | |
1175 | * doing direct I/O, some references remain after try_to_unmap() and | |
1176 | * hugepage migration fails without data corruption. | |
1177 | * | |
1178 | * There is also no race when direct I/O is issued on the page under migration, | |
1179 | * because then pte is replaced with migration swap entry and direct I/O code | |
1180 | * will wait in the page fault for migration to complete. | |
1181 | */ | |
1182 | static int unmap_and_move_huge_page(new_page_t get_new_page, | |
68711a74 DR |
1183 | free_page_t put_new_page, unsigned long private, |
1184 | struct page *hpage, int force, | |
7cd12b4a | 1185 | enum migrate_mode mode, int reason) |
290408d4 | 1186 | { |
2def7424 | 1187 | int rc = -EAGAIN; |
290408d4 | 1188 | int *result = NULL; |
2ebba6b7 | 1189 | int page_was_mapped = 0; |
32665f2b | 1190 | struct page *new_hpage; |
290408d4 NH |
1191 | struct anon_vma *anon_vma = NULL; |
1192 | ||
83467efb NH |
1193 | /* |
1194 | * Movability of hugepages depends on architectures and hugepage size. | |
1195 | * This check is necessary because some callers of hugepage migration | |
1196 | * like soft offline and memory hotremove don't walk through page | |
1197 | * tables or check whether the hugepage is pmd-based or not before | |
1198 | * kicking migration. | |
1199 | */ | |
100873d7 | 1200 | if (!hugepage_migration_supported(page_hstate(hpage))) { |
32665f2b | 1201 | putback_active_hugepage(hpage); |
83467efb | 1202 | return -ENOSYS; |
32665f2b | 1203 | } |
83467efb | 1204 | |
32665f2b | 1205 | new_hpage = get_new_page(hpage, private, &result); |
290408d4 NH |
1206 | if (!new_hpage) |
1207 | return -ENOMEM; | |
1208 | ||
290408d4 | 1209 | if (!trylock_page(hpage)) { |
a6bc32b8 | 1210 | if (!force || mode != MIGRATE_SYNC) |
290408d4 NH |
1211 | goto out; |
1212 | lock_page(hpage); | |
1213 | } | |
1214 | ||
746b18d4 PZ |
1215 | if (PageAnon(hpage)) |
1216 | anon_vma = page_get_anon_vma(hpage); | |
290408d4 | 1217 | |
7db7671f HD |
1218 | if (unlikely(!trylock_page(new_hpage))) |
1219 | goto put_anon; | |
1220 | ||
2ebba6b7 HD |
1221 | if (page_mapped(hpage)) { |
1222 | try_to_unmap(hpage, | |
1223 | TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS); | |
1224 | page_was_mapped = 1; | |
1225 | } | |
290408d4 NH |
1226 | |
1227 | if (!page_mapped(hpage)) | |
5c3f9a67 | 1228 | rc = move_to_new_page(new_hpage, hpage, mode); |
290408d4 | 1229 | |
5c3f9a67 HD |
1230 | if (page_was_mapped) |
1231 | remove_migration_ptes(hpage, | |
e388466d | 1232 | rc == MIGRATEPAGE_SUCCESS ? new_hpage : hpage, false); |
290408d4 | 1233 | |
7db7671f HD |
1234 | unlock_page(new_hpage); |
1235 | ||
1236 | put_anon: | |
fd4a4663 | 1237 | if (anon_vma) |
9e60109f | 1238 | put_anon_vma(anon_vma); |
8e6ac7fa | 1239 | |
2def7424 | 1240 | if (rc == MIGRATEPAGE_SUCCESS) { |
8e6ac7fa | 1241 | hugetlb_cgroup_migrate(hpage, new_hpage); |
2def7424 | 1242 | put_new_page = NULL; |
7cd12b4a | 1243 | set_page_owner_migrate_reason(new_hpage, reason); |
2def7424 | 1244 | } |
8e6ac7fa | 1245 | |
290408d4 | 1246 | unlock_page(hpage); |
09761333 | 1247 | out: |
b8ec1cee NH |
1248 | if (rc != -EAGAIN) |
1249 | putback_active_hugepage(hpage); | |
68711a74 DR |
1250 | |
1251 | /* | |
1252 | * If migration was not successful and there's a freeing callback, use | |
1253 | * it. Otherwise, put_page() will drop the reference grabbed during | |
1254 | * isolation. | |
1255 | */ | |
2def7424 | 1256 | if (put_new_page) |
68711a74 DR |
1257 | put_new_page(new_hpage, private); |
1258 | else | |
3aaa76e1 | 1259 | putback_active_hugepage(new_hpage); |
68711a74 | 1260 | |
290408d4 NH |
1261 | if (result) { |
1262 | if (rc) | |
1263 | *result = rc; | |
1264 | else | |
1265 | *result = page_to_nid(new_hpage); | |
1266 | } | |
1267 | return rc; | |
1268 | } | |
1269 | ||
b20a3503 | 1270 | /* |
c73e5c9c SB |
1271 | * migrate_pages - migrate the pages specified in a list, to the free pages |
1272 | * supplied as the target for the page migration | |
b20a3503 | 1273 | * |
c73e5c9c SB |
1274 | * @from: The list of pages to be migrated. |
1275 | * @get_new_page: The function used to allocate free pages to be used | |
1276 | * as the target of the page migration. | |
68711a74 DR |
1277 | * @put_new_page: The function used to free target pages if migration |
1278 | * fails, or NULL if no special handling is necessary. | |
c73e5c9c SB |
1279 | * @private: Private data to be passed on to get_new_page() |
1280 | * @mode: The migration mode that specifies the constraints for | |
1281 | * page migration, if any. | |
1282 | * @reason: The reason for page migration. | |
b20a3503 | 1283 | * |
c73e5c9c SB |
1284 | * The function returns after 10 attempts or if no pages are movable any more |
1285 | * because the list has become empty or no retryable pages exist any more. | |
14e0f9bc | 1286 | * The caller should call putback_movable_pages() to return pages to the LRU |
28bd6578 | 1287 | * or free list only if ret != 0. |
b20a3503 | 1288 | * |
c73e5c9c | 1289 | * Returns the number of pages that were not migrated, or an error code. |
b20a3503 | 1290 | */ |
9c620e2b | 1291 | int migrate_pages(struct list_head *from, new_page_t get_new_page, |
68711a74 DR |
1292 | free_page_t put_new_page, unsigned long private, |
1293 | enum migrate_mode mode, int reason) | |
b20a3503 | 1294 | { |
e24f0b8f | 1295 | int retry = 1; |
b20a3503 | 1296 | int nr_failed = 0; |
5647bc29 | 1297 | int nr_succeeded = 0; |
b20a3503 CL |
1298 | int pass = 0; |
1299 | struct page *page; | |
1300 | struct page *page2; | |
1301 | int swapwrite = current->flags & PF_SWAPWRITE; | |
1302 | int rc; | |
1303 | ||
1304 | if (!swapwrite) | |
1305 | current->flags |= PF_SWAPWRITE; | |
1306 | ||
e24f0b8f CL |
1307 | for(pass = 0; pass < 10 && retry; pass++) { |
1308 | retry = 0; | |
b20a3503 | 1309 | |
e24f0b8f | 1310 | list_for_each_entry_safe(page, page2, from, lru) { |
e24f0b8f | 1311 | cond_resched(); |
2d1db3b1 | 1312 | |
31caf665 NH |
1313 | if (PageHuge(page)) |
1314 | rc = unmap_and_move_huge_page(get_new_page, | |
68711a74 | 1315 | put_new_page, private, page, |
7cd12b4a | 1316 | pass > 2, mode, reason); |
31caf665 | 1317 | else |
68711a74 | 1318 | rc = unmap_and_move(get_new_page, put_new_page, |
add05cec NH |
1319 | private, page, pass > 2, mode, |
1320 | reason); | |
2d1db3b1 | 1321 | |
e24f0b8f | 1322 | switch(rc) { |
95a402c3 | 1323 | case -ENOMEM: |
dfef2ef4 | 1324 | nr_failed++; |
95a402c3 | 1325 | goto out; |
e24f0b8f | 1326 | case -EAGAIN: |
2d1db3b1 | 1327 | retry++; |
e24f0b8f | 1328 | break; |
78bd5209 | 1329 | case MIGRATEPAGE_SUCCESS: |
5647bc29 | 1330 | nr_succeeded++; |
e24f0b8f CL |
1331 | break; |
1332 | default: | |
354a3363 NH |
1333 | /* |
1334 | * Permanent failure (-EBUSY, -ENOSYS, etc.): | |
1335 | * unlike -EAGAIN case, the failed page is | |
1336 | * removed from migration page list and not | |
1337 | * retried in the next outer loop. | |
1338 | */ | |
2d1db3b1 | 1339 | nr_failed++; |
e24f0b8f | 1340 | break; |
2d1db3b1 | 1341 | } |
b20a3503 CL |
1342 | } |
1343 | } | |
f2f81fb2 VB |
1344 | nr_failed += retry; |
1345 | rc = nr_failed; | |
95a402c3 | 1346 | out: |
5647bc29 MG |
1347 | if (nr_succeeded) |
1348 | count_vm_events(PGMIGRATE_SUCCESS, nr_succeeded); | |
1349 | if (nr_failed) | |
1350 | count_vm_events(PGMIGRATE_FAIL, nr_failed); | |
7b2a2d4a MG |
1351 | trace_mm_migrate_pages(nr_succeeded, nr_failed, mode, reason); |
1352 | ||
b20a3503 CL |
1353 | if (!swapwrite) |
1354 | current->flags &= ~PF_SWAPWRITE; | |
1355 | ||
78bd5209 | 1356 | return rc; |
b20a3503 | 1357 | } |
95a402c3 | 1358 | |
742755a1 CL |
1359 | #ifdef CONFIG_NUMA |
1360 | /* | |
1361 | * Move a list of individual pages | |
1362 | */ | |
1363 | struct page_to_node { | |
1364 | unsigned long addr; | |
1365 | struct page *page; | |
1366 | int node; | |
1367 | int status; | |
1368 | }; | |
1369 | ||
1370 | static struct page *new_page_node(struct page *p, unsigned long private, | |
1371 | int **result) | |
1372 | { | |
1373 | struct page_to_node *pm = (struct page_to_node *)private; | |
1374 | ||
1375 | while (pm->node != MAX_NUMNODES && pm->page != p) | |
1376 | pm++; | |
1377 | ||
1378 | if (pm->node == MAX_NUMNODES) | |
1379 | return NULL; | |
1380 | ||
1381 | *result = &pm->status; | |
1382 | ||
e632a938 NH |
1383 | if (PageHuge(p)) |
1384 | return alloc_huge_page_node(page_hstate(compound_head(p)), | |
1385 | pm->node); | |
1386 | else | |
96db800f | 1387 | return __alloc_pages_node(pm->node, |
e97ca8e5 | 1388 | GFP_HIGHUSER_MOVABLE | __GFP_THISNODE, 0); |
742755a1 CL |
1389 | } |
1390 | ||
1391 | /* | |
1392 | * Move a set of pages as indicated in the pm array. The addr | |
1393 | * field must be set to the virtual address of the page to be moved | |
1394 | * and the node number must contain a valid target node. | |
5e9a0f02 | 1395 | * The pm array ends with node = MAX_NUMNODES. |
742755a1 | 1396 | */ |
5e9a0f02 BG |
1397 | static int do_move_page_to_node_array(struct mm_struct *mm, |
1398 | struct page_to_node *pm, | |
1399 | int migrate_all) | |
742755a1 CL |
1400 | { |
1401 | int err; | |
1402 | struct page_to_node *pp; | |
1403 | LIST_HEAD(pagelist); | |
1404 | ||
1405 | down_read(&mm->mmap_sem); | |
1406 | ||
1407 | /* | |
1408 | * Build a list of pages to migrate | |
1409 | */ | |
742755a1 CL |
1410 | for (pp = pm; pp->node != MAX_NUMNODES; pp++) { |
1411 | struct vm_area_struct *vma; | |
1412 | struct page *page; | |
1413 | ||
742755a1 CL |
1414 | err = -EFAULT; |
1415 | vma = find_vma(mm, pp->addr); | |
70384dc6 | 1416 | if (!vma || pp->addr < vma->vm_start || !vma_migratable(vma)) |
742755a1 CL |
1417 | goto set_status; |
1418 | ||
d899844e KS |
1419 | /* FOLL_DUMP to ignore special (like zero) pages */ |
1420 | page = follow_page(vma, pp->addr, | |
1421 | FOLL_GET | FOLL_SPLIT | FOLL_DUMP); | |
89f5b7da LT |
1422 | |
1423 | err = PTR_ERR(page); | |
1424 | if (IS_ERR(page)) | |
1425 | goto set_status; | |
1426 | ||
742755a1 CL |
1427 | err = -ENOENT; |
1428 | if (!page) | |
1429 | goto set_status; | |
1430 | ||
742755a1 CL |
1431 | pp->page = page; |
1432 | err = page_to_nid(page); | |
1433 | ||
1434 | if (err == pp->node) | |
1435 | /* | |
1436 | * Node already in the right place | |
1437 | */ | |
1438 | goto put_and_set; | |
1439 | ||
1440 | err = -EACCES; | |
1441 | if (page_mapcount(page) > 1 && | |
1442 | !migrate_all) | |
1443 | goto put_and_set; | |
1444 | ||
e632a938 | 1445 | if (PageHuge(page)) { |
e66f17ff NH |
1446 | if (PageHead(page)) |
1447 | isolate_huge_page(page, &pagelist); | |
e632a938 NH |
1448 | goto put_and_set; |
1449 | } | |
1450 | ||
62695a84 | 1451 | err = isolate_lru_page(page); |
6d9c285a | 1452 | if (!err) { |
62695a84 | 1453 | list_add_tail(&page->lru, &pagelist); |
599d0c95 | 1454 | inc_node_page_state(page, NR_ISOLATED_ANON + |
6d9c285a KM |
1455 | page_is_file_cache(page)); |
1456 | } | |
742755a1 CL |
1457 | put_and_set: |
1458 | /* | |
1459 | * Either remove the duplicate refcount from | |
1460 | * isolate_lru_page() or drop the page ref if it was | |
1461 | * not isolated. | |
1462 | */ | |
1463 | put_page(page); | |
1464 | set_status: | |
1465 | pp->status = err; | |
1466 | } | |
1467 | ||
e78bbfa8 | 1468 | err = 0; |
cf608ac1 | 1469 | if (!list_empty(&pagelist)) { |
68711a74 | 1470 | err = migrate_pages(&pagelist, new_page_node, NULL, |
9c620e2b | 1471 | (unsigned long)pm, MIGRATE_SYNC, MR_SYSCALL); |
cf608ac1 | 1472 | if (err) |
e632a938 | 1473 | putback_movable_pages(&pagelist); |
cf608ac1 | 1474 | } |
742755a1 CL |
1475 | |
1476 | up_read(&mm->mmap_sem); | |
1477 | return err; | |
1478 | } | |
1479 | ||
5e9a0f02 BG |
1480 | /* |
1481 | * Migrate an array of page address onto an array of nodes and fill | |
1482 | * the corresponding array of status. | |
1483 | */ | |
3268c63e | 1484 | static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, |
5e9a0f02 BG |
1485 | unsigned long nr_pages, |
1486 | const void __user * __user *pages, | |
1487 | const int __user *nodes, | |
1488 | int __user *status, int flags) | |
1489 | { | |
3140a227 | 1490 | struct page_to_node *pm; |
3140a227 BG |
1491 | unsigned long chunk_nr_pages; |
1492 | unsigned long chunk_start; | |
1493 | int err; | |
5e9a0f02 | 1494 | |
3140a227 BG |
1495 | err = -ENOMEM; |
1496 | pm = (struct page_to_node *)__get_free_page(GFP_KERNEL); | |
1497 | if (!pm) | |
5e9a0f02 | 1498 | goto out; |
35282a2d BG |
1499 | |
1500 | migrate_prep(); | |
1501 | ||
5e9a0f02 | 1502 | /* |
3140a227 BG |
1503 | * Store a chunk of page_to_node array in a page, |
1504 | * but keep the last one as a marker | |
5e9a0f02 | 1505 | */ |
3140a227 | 1506 | chunk_nr_pages = (PAGE_SIZE / sizeof(struct page_to_node)) - 1; |
5e9a0f02 | 1507 | |
3140a227 BG |
1508 | for (chunk_start = 0; |
1509 | chunk_start < nr_pages; | |
1510 | chunk_start += chunk_nr_pages) { | |
1511 | int j; | |
5e9a0f02 | 1512 | |
3140a227 BG |
1513 | if (chunk_start + chunk_nr_pages > nr_pages) |
1514 | chunk_nr_pages = nr_pages - chunk_start; | |
1515 | ||
1516 | /* fill the chunk pm with addrs and nodes from user-space */ | |
1517 | for (j = 0; j < chunk_nr_pages; j++) { | |
1518 | const void __user *p; | |
5e9a0f02 BG |
1519 | int node; |
1520 | ||
3140a227 BG |
1521 | err = -EFAULT; |
1522 | if (get_user(p, pages + j + chunk_start)) | |
1523 | goto out_pm; | |
1524 | pm[j].addr = (unsigned long) p; | |
1525 | ||
1526 | if (get_user(node, nodes + j + chunk_start)) | |
5e9a0f02 BG |
1527 | goto out_pm; |
1528 | ||
1529 | err = -ENODEV; | |
6f5a55f1 LT |
1530 | if (node < 0 || node >= MAX_NUMNODES) |
1531 | goto out_pm; | |
1532 | ||
389162c2 | 1533 | if (!node_state(node, N_MEMORY)) |
5e9a0f02 BG |
1534 | goto out_pm; |
1535 | ||
1536 | err = -EACCES; | |
1537 | if (!node_isset(node, task_nodes)) | |
1538 | goto out_pm; | |
1539 | ||
3140a227 BG |
1540 | pm[j].node = node; |
1541 | } | |
1542 | ||
1543 | /* End marker for this chunk */ | |
1544 | pm[chunk_nr_pages].node = MAX_NUMNODES; | |
1545 | ||
1546 | /* Migrate this chunk */ | |
1547 | err = do_move_page_to_node_array(mm, pm, | |
1548 | flags & MPOL_MF_MOVE_ALL); | |
1549 | if (err < 0) | |
1550 | goto out_pm; | |
5e9a0f02 | 1551 | |
5e9a0f02 | 1552 | /* Return status information */ |
3140a227 BG |
1553 | for (j = 0; j < chunk_nr_pages; j++) |
1554 | if (put_user(pm[j].status, status + j + chunk_start)) { | |
5e9a0f02 | 1555 | err = -EFAULT; |
3140a227 BG |
1556 | goto out_pm; |
1557 | } | |
1558 | } | |
1559 | err = 0; | |
5e9a0f02 BG |
1560 | |
1561 | out_pm: | |
3140a227 | 1562 | free_page((unsigned long)pm); |
5e9a0f02 BG |
1563 | out: |
1564 | return err; | |
1565 | } | |
1566 | ||
742755a1 | 1567 | /* |
2f007e74 | 1568 | * Determine the nodes of an array of pages and store it in an array of status. |
742755a1 | 1569 | */ |
80bba129 BG |
1570 | static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages, |
1571 | const void __user **pages, int *status) | |
742755a1 | 1572 | { |
2f007e74 | 1573 | unsigned long i; |
2f007e74 | 1574 | |
742755a1 CL |
1575 | down_read(&mm->mmap_sem); |
1576 | ||
2f007e74 | 1577 | for (i = 0; i < nr_pages; i++) { |
80bba129 | 1578 | unsigned long addr = (unsigned long)(*pages); |
742755a1 CL |
1579 | struct vm_area_struct *vma; |
1580 | struct page *page; | |
c095adbc | 1581 | int err = -EFAULT; |
2f007e74 BG |
1582 | |
1583 | vma = find_vma(mm, addr); | |
70384dc6 | 1584 | if (!vma || addr < vma->vm_start) |
742755a1 CL |
1585 | goto set_status; |
1586 | ||
d899844e KS |
1587 | /* FOLL_DUMP to ignore special (like zero) pages */ |
1588 | page = follow_page(vma, addr, FOLL_DUMP); | |
89f5b7da LT |
1589 | |
1590 | err = PTR_ERR(page); | |
1591 | if (IS_ERR(page)) | |
1592 | goto set_status; | |
1593 | ||
d899844e | 1594 | err = page ? page_to_nid(page) : -ENOENT; |
742755a1 | 1595 | set_status: |
80bba129 BG |
1596 | *status = err; |
1597 | ||
1598 | pages++; | |
1599 | status++; | |
1600 | } | |
1601 | ||
1602 | up_read(&mm->mmap_sem); | |
1603 | } | |
1604 | ||
1605 | /* | |
1606 | * Determine the nodes of a user array of pages and store it in | |
1607 | * a user array of status. | |
1608 | */ | |
1609 | static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages, | |
1610 | const void __user * __user *pages, | |
1611 | int __user *status) | |
1612 | { | |
1613 | #define DO_PAGES_STAT_CHUNK_NR 16 | |
1614 | const void __user *chunk_pages[DO_PAGES_STAT_CHUNK_NR]; | |
1615 | int chunk_status[DO_PAGES_STAT_CHUNK_NR]; | |
80bba129 | 1616 | |
87b8d1ad PA |
1617 | while (nr_pages) { |
1618 | unsigned long chunk_nr; | |
80bba129 | 1619 | |
87b8d1ad PA |
1620 | chunk_nr = nr_pages; |
1621 | if (chunk_nr > DO_PAGES_STAT_CHUNK_NR) | |
1622 | chunk_nr = DO_PAGES_STAT_CHUNK_NR; | |
1623 | ||
1624 | if (copy_from_user(chunk_pages, pages, chunk_nr * sizeof(*chunk_pages))) | |
1625 | break; | |
80bba129 BG |
1626 | |
1627 | do_pages_stat_array(mm, chunk_nr, chunk_pages, chunk_status); | |
1628 | ||
87b8d1ad PA |
1629 | if (copy_to_user(status, chunk_status, chunk_nr * sizeof(*status))) |
1630 | break; | |
742755a1 | 1631 | |
87b8d1ad PA |
1632 | pages += chunk_nr; |
1633 | status += chunk_nr; | |
1634 | nr_pages -= chunk_nr; | |
1635 | } | |
1636 | return nr_pages ? -EFAULT : 0; | |
742755a1 CL |
1637 | } |
1638 | ||
1639 | /* | |
1640 | * Move a list of pages in the address space of the currently executing | |
1641 | * process. | |
1642 | */ | |
938bb9f5 HC |
1643 | SYSCALL_DEFINE6(move_pages, pid_t, pid, unsigned long, nr_pages, |
1644 | const void __user * __user *, pages, | |
1645 | const int __user *, nodes, | |
1646 | int __user *, status, int, flags) | |
742755a1 | 1647 | { |
c69e8d9c | 1648 | const struct cred *cred = current_cred(), *tcred; |
742755a1 | 1649 | struct task_struct *task; |
742755a1 | 1650 | struct mm_struct *mm; |
5e9a0f02 | 1651 | int err; |
3268c63e | 1652 | nodemask_t task_nodes; |
742755a1 CL |
1653 | |
1654 | /* Check flags */ | |
1655 | if (flags & ~(MPOL_MF_MOVE|MPOL_MF_MOVE_ALL)) | |
1656 | return -EINVAL; | |
1657 | ||
1658 | if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE)) | |
1659 | return -EPERM; | |
1660 | ||
1661 | /* Find the mm_struct */ | |
a879bf58 | 1662 | rcu_read_lock(); |
228ebcbe | 1663 | task = pid ? find_task_by_vpid(pid) : current; |
742755a1 | 1664 | if (!task) { |
a879bf58 | 1665 | rcu_read_unlock(); |
742755a1 CL |
1666 | return -ESRCH; |
1667 | } | |
3268c63e | 1668 | get_task_struct(task); |
742755a1 CL |
1669 | |
1670 | /* | |
1671 | * Check if this process has the right to modify the specified | |
1672 | * process. The right exists if the process has administrative | |
1673 | * capabilities, superuser privileges or the same | |
1674 | * userid as the target process. | |
1675 | */ | |
c69e8d9c | 1676 | tcred = __task_cred(task); |
b38a86eb EB |
1677 | if (!uid_eq(cred->euid, tcred->suid) && !uid_eq(cred->euid, tcred->uid) && |
1678 | !uid_eq(cred->uid, tcred->suid) && !uid_eq(cred->uid, tcred->uid) && | |
742755a1 | 1679 | !capable(CAP_SYS_NICE)) { |
c69e8d9c | 1680 | rcu_read_unlock(); |
742755a1 | 1681 | err = -EPERM; |
5e9a0f02 | 1682 | goto out; |
742755a1 | 1683 | } |
c69e8d9c | 1684 | rcu_read_unlock(); |
742755a1 | 1685 | |
86c3a764 DQ |
1686 | err = security_task_movememory(task); |
1687 | if (err) | |
5e9a0f02 | 1688 | goto out; |
86c3a764 | 1689 | |
3268c63e CL |
1690 | task_nodes = cpuset_mems_allowed(task); |
1691 | mm = get_task_mm(task); | |
1692 | put_task_struct(task); | |
1693 | ||
6e8b09ea SL |
1694 | if (!mm) |
1695 | return -EINVAL; | |
1696 | ||
1697 | if (nodes) | |
1698 | err = do_pages_move(mm, task_nodes, nr_pages, pages, | |
1699 | nodes, status, flags); | |
1700 | else | |
1701 | err = do_pages_stat(mm, nr_pages, pages, status); | |
742755a1 | 1702 | |
742755a1 CL |
1703 | mmput(mm); |
1704 | return err; | |
3268c63e CL |
1705 | |
1706 | out: | |
1707 | put_task_struct(task); | |
1708 | return err; | |
742755a1 | 1709 | } |
742755a1 | 1710 | |
7039e1db PZ |
1711 | #ifdef CONFIG_NUMA_BALANCING |
1712 | /* | |
1713 | * Returns true if this is a safe migration target node for misplaced NUMA | |
1714 | * pages. Currently it only checks the watermarks which crude | |
1715 | */ | |
1716 | static bool migrate_balanced_pgdat(struct pglist_data *pgdat, | |
3abef4e6 | 1717 | unsigned long nr_migrate_pages) |
7039e1db PZ |
1718 | { |
1719 | int z; | |
599d0c95 MG |
1720 | |
1721 | if (!pgdat_reclaimable(pgdat)) | |
1722 | return false; | |
1723 | ||
7039e1db PZ |
1724 | for (z = pgdat->nr_zones - 1; z >= 0; z--) { |
1725 | struct zone *zone = pgdat->node_zones + z; | |
1726 | ||
1727 | if (!populated_zone(zone)) | |
1728 | continue; | |
1729 | ||
7039e1db PZ |
1730 | /* Avoid waking kswapd by allocating pages_to_migrate pages. */ |
1731 | if (!zone_watermark_ok(zone, 0, | |
1732 | high_wmark_pages(zone) + | |
1733 | nr_migrate_pages, | |
1734 | 0, 0)) | |
1735 | continue; | |
1736 | return true; | |
1737 | } | |
1738 | return false; | |
1739 | } | |
1740 | ||
1741 | static struct page *alloc_misplaced_dst_page(struct page *page, | |
1742 | unsigned long data, | |
1743 | int **result) | |
1744 | { | |
1745 | int nid = (int) data; | |
1746 | struct page *newpage; | |
1747 | ||
96db800f | 1748 | newpage = __alloc_pages_node(nid, |
e97ca8e5 JW |
1749 | (GFP_HIGHUSER_MOVABLE | |
1750 | __GFP_THISNODE | __GFP_NOMEMALLOC | | |
1751 | __GFP_NORETRY | __GFP_NOWARN) & | |
8479eba7 | 1752 | ~__GFP_RECLAIM, 0); |
bac0382c | 1753 | |
7039e1db PZ |
1754 | return newpage; |
1755 | } | |
1756 | ||
a8f60772 MG |
1757 | /* |
1758 | * page migration rate limiting control. | |
1759 | * Do not migrate more than @pages_to_migrate in a @migrate_interval_millisecs | |
1760 | * window of time. Default here says do not migrate more than 1280M per second. | |
1761 | */ | |
1762 | static unsigned int migrate_interval_millisecs __read_mostly = 100; | |
1763 | static unsigned int ratelimit_pages __read_mostly = 128 << (20 - PAGE_SHIFT); | |
1764 | ||
b32967ff | 1765 | /* Returns true if the node is migrate rate-limited after the update */ |
1c30e017 MG |
1766 | static bool numamigrate_update_ratelimit(pg_data_t *pgdat, |
1767 | unsigned long nr_pages) | |
7039e1db | 1768 | { |
a8f60772 MG |
1769 | /* |
1770 | * Rate-limit the amount of data that is being migrated to a node. | |
1771 | * Optimal placement is no good if the memory bus is saturated and | |
1772 | * all the time is being spent migrating! | |
1773 | */ | |
a8f60772 | 1774 | if (time_after(jiffies, pgdat->numabalancing_migrate_next_window)) { |
1c5e9c27 | 1775 | spin_lock(&pgdat->numabalancing_migrate_lock); |
a8f60772 MG |
1776 | pgdat->numabalancing_migrate_nr_pages = 0; |
1777 | pgdat->numabalancing_migrate_next_window = jiffies + | |
1778 | msecs_to_jiffies(migrate_interval_millisecs); | |
1c5e9c27 | 1779 | spin_unlock(&pgdat->numabalancing_migrate_lock); |
a8f60772 | 1780 | } |
af1839d7 MG |
1781 | if (pgdat->numabalancing_migrate_nr_pages > ratelimit_pages) { |
1782 | trace_mm_numa_migrate_ratelimit(current, pgdat->node_id, | |
1783 | nr_pages); | |
1c5e9c27 | 1784 | return true; |
af1839d7 | 1785 | } |
1c5e9c27 MG |
1786 | |
1787 | /* | |
1788 | * This is an unlocked non-atomic update so errors are possible. | |
1789 | * The consequences are failing to migrate when we potentiall should | |
1790 | * have which is not severe enough to warrant locking. If it is ever | |
1791 | * a problem, it can be converted to a per-cpu counter. | |
1792 | */ | |
1793 | pgdat->numabalancing_migrate_nr_pages += nr_pages; | |
1794 | return false; | |
b32967ff MG |
1795 | } |
1796 | ||
1c30e017 | 1797 | static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page) |
b32967ff | 1798 | { |
340ef390 | 1799 | int page_lru; |
a8f60772 | 1800 | |
309381fe | 1801 | VM_BUG_ON_PAGE(compound_order(page) && !PageTransHuge(page), page); |
3abef4e6 | 1802 | |
7039e1db | 1803 | /* Avoid migrating to a node that is nearly full */ |
340ef390 HD |
1804 | if (!migrate_balanced_pgdat(pgdat, 1UL << compound_order(page))) |
1805 | return 0; | |
7039e1db | 1806 | |
340ef390 HD |
1807 | if (isolate_lru_page(page)) |
1808 | return 0; | |
7039e1db | 1809 | |
340ef390 HD |
1810 | /* |
1811 | * migrate_misplaced_transhuge_page() skips page migration's usual | |
1812 | * check on page_count(), so we must do it here, now that the page | |
1813 | * has been isolated: a GUP pin, or any other pin, prevents migration. | |
1814 | * The expected page count is 3: 1 for page's mapcount and 1 for the | |
1815 | * caller's pin and 1 for the reference taken by isolate_lru_page(). | |
1816 | */ | |
1817 | if (PageTransHuge(page) && page_count(page) != 3) { | |
1818 | putback_lru_page(page); | |
1819 | return 0; | |
7039e1db PZ |
1820 | } |
1821 | ||
340ef390 | 1822 | page_lru = page_is_file_cache(page); |
599d0c95 | 1823 | mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON + page_lru, |
340ef390 HD |
1824 | hpage_nr_pages(page)); |
1825 | ||
149c33e1 | 1826 | /* |
340ef390 HD |
1827 | * Isolating the page has taken another reference, so the |
1828 | * caller's reference can be safely dropped without the page | |
1829 | * disappearing underneath us during migration. | |
149c33e1 MG |
1830 | */ |
1831 | put_page(page); | |
340ef390 | 1832 | return 1; |
b32967ff MG |
1833 | } |
1834 | ||
de466bd6 MG |
1835 | bool pmd_trans_migrating(pmd_t pmd) |
1836 | { | |
1837 | struct page *page = pmd_page(pmd); | |
1838 | return PageLocked(page); | |
1839 | } | |
1840 | ||
b32967ff MG |
1841 | /* |
1842 | * Attempt to migrate a misplaced page to the specified destination | |
1843 | * node. Caller is expected to have an elevated reference count on | |
1844 | * the page that will be dropped by this function before returning. | |
1845 | */ | |
1bc115d8 MG |
1846 | int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma, |
1847 | int node) | |
b32967ff MG |
1848 | { |
1849 | pg_data_t *pgdat = NODE_DATA(node); | |
340ef390 | 1850 | int isolated; |
b32967ff MG |
1851 | int nr_remaining; |
1852 | LIST_HEAD(migratepages); | |
1853 | ||
1854 | /* | |
1bc115d8 MG |
1855 | * Don't migrate file pages that are mapped in multiple processes |
1856 | * with execute permissions as they are probably shared libraries. | |
b32967ff | 1857 | */ |
1bc115d8 MG |
1858 | if (page_mapcount(page) != 1 && page_is_file_cache(page) && |
1859 | (vma->vm_flags & VM_EXEC)) | |
b32967ff | 1860 | goto out; |
b32967ff MG |
1861 | |
1862 | /* | |
1863 | * Rate-limit the amount of data that is being migrated to a node. | |
1864 | * Optimal placement is no good if the memory bus is saturated and | |
1865 | * all the time is being spent migrating! | |
1866 | */ | |
340ef390 | 1867 | if (numamigrate_update_ratelimit(pgdat, 1)) |
b32967ff | 1868 | goto out; |
b32967ff MG |
1869 | |
1870 | isolated = numamigrate_isolate_page(pgdat, page); | |
1871 | if (!isolated) | |
1872 | goto out; | |
1873 | ||
1874 | list_add(&page->lru, &migratepages); | |
9c620e2b | 1875 | nr_remaining = migrate_pages(&migratepages, alloc_misplaced_dst_page, |
68711a74 DR |
1876 | NULL, node, MIGRATE_ASYNC, |
1877 | MR_NUMA_MISPLACED); | |
b32967ff | 1878 | if (nr_remaining) { |
59c82b70 JK |
1879 | if (!list_empty(&migratepages)) { |
1880 | list_del(&page->lru); | |
599d0c95 | 1881 | dec_node_page_state(page, NR_ISOLATED_ANON + |
59c82b70 JK |
1882 | page_is_file_cache(page)); |
1883 | putback_lru_page(page); | |
1884 | } | |
b32967ff MG |
1885 | isolated = 0; |
1886 | } else | |
1887 | count_vm_numa_event(NUMA_PAGE_MIGRATE); | |
7039e1db | 1888 | BUG_ON(!list_empty(&migratepages)); |
7039e1db | 1889 | return isolated; |
340ef390 HD |
1890 | |
1891 | out: | |
1892 | put_page(page); | |
1893 | return 0; | |
7039e1db | 1894 | } |
220018d3 | 1895 | #endif /* CONFIG_NUMA_BALANCING */ |
b32967ff | 1896 | |
220018d3 | 1897 | #if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE) |
340ef390 HD |
1898 | /* |
1899 | * Migrates a THP to a given target node. page must be locked and is unlocked | |
1900 | * before returning. | |
1901 | */ | |
b32967ff MG |
1902 | int migrate_misplaced_transhuge_page(struct mm_struct *mm, |
1903 | struct vm_area_struct *vma, | |
1904 | pmd_t *pmd, pmd_t entry, | |
1905 | unsigned long address, | |
1906 | struct page *page, int node) | |
1907 | { | |
c4088ebd | 1908 | spinlock_t *ptl; |
b32967ff MG |
1909 | pg_data_t *pgdat = NODE_DATA(node); |
1910 | int isolated = 0; | |
1911 | struct page *new_page = NULL; | |
b32967ff | 1912 | int page_lru = page_is_file_cache(page); |
f714f4f2 MG |
1913 | unsigned long mmun_start = address & HPAGE_PMD_MASK; |
1914 | unsigned long mmun_end = mmun_start + HPAGE_PMD_SIZE; | |
2b4847e7 | 1915 | pmd_t orig_entry; |
b32967ff | 1916 | |
b32967ff MG |
1917 | /* |
1918 | * Rate-limit the amount of data that is being migrated to a node. | |
1919 | * Optimal placement is no good if the memory bus is saturated and | |
1920 | * all the time is being spent migrating! | |
1921 | */ | |
d28d4335 | 1922 | if (numamigrate_update_ratelimit(pgdat, HPAGE_PMD_NR)) |
b32967ff MG |
1923 | goto out_dropref; |
1924 | ||
1925 | new_page = alloc_pages_node(node, | |
25160354 | 1926 | (GFP_TRANSHUGE_LIGHT | __GFP_THISNODE), |
e97ca8e5 | 1927 | HPAGE_PMD_ORDER); |
340ef390 HD |
1928 | if (!new_page) |
1929 | goto out_fail; | |
9a982250 | 1930 | prep_transhuge_page(new_page); |
340ef390 | 1931 | |
b32967ff | 1932 | isolated = numamigrate_isolate_page(pgdat, page); |
340ef390 | 1933 | if (!isolated) { |
b32967ff | 1934 | put_page(new_page); |
340ef390 | 1935 | goto out_fail; |
b32967ff | 1936 | } |
458aa76d AK |
1937 | /* |
1938 | * We are not sure a pending tlb flush here is for a huge page | |
1939 | * mapping or not. Hence use the tlb range variant | |
1940 | */ | |
b0943d61 MG |
1941 | if (mm_tlb_flush_pending(mm)) |
1942 | flush_tlb_range(vma, mmun_start, mmun_end); | |
1943 | ||
b32967ff | 1944 | /* Prepare a page as a migration target */ |
48c935ad | 1945 | __SetPageLocked(new_page); |
fa9949da | 1946 | __SetPageSwapBacked(new_page); |
b32967ff MG |
1947 | |
1948 | /* anon mapping, we can simply copy page->mapping to the new page: */ | |
1949 | new_page->mapping = page->mapping; | |
1950 | new_page->index = page->index; | |
1951 | migrate_page_copy(new_page, page); | |
1952 | WARN_ON(PageLRU(new_page)); | |
1953 | ||
1954 | /* Recheck the target PMD */ | |
f714f4f2 | 1955 | mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end); |
c4088ebd | 1956 | ptl = pmd_lock(mm, pmd); |
2b4847e7 MG |
1957 | if (unlikely(!pmd_same(*pmd, entry) || page_count(page) != 2)) { |
1958 | fail_putback: | |
c4088ebd | 1959 | spin_unlock(ptl); |
f714f4f2 | 1960 | mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); |
b32967ff MG |
1961 | |
1962 | /* Reverse changes made by migrate_page_copy() */ | |
1963 | if (TestClearPageActive(new_page)) | |
1964 | SetPageActive(page); | |
1965 | if (TestClearPageUnevictable(new_page)) | |
1966 | SetPageUnevictable(page); | |
b32967ff MG |
1967 | |
1968 | unlock_page(new_page); | |
1969 | put_page(new_page); /* Free it */ | |
1970 | ||
a54a407f MG |
1971 | /* Retake the callers reference and putback on LRU */ |
1972 | get_page(page); | |
b32967ff | 1973 | putback_lru_page(page); |
599d0c95 | 1974 | mod_node_page_state(page_pgdat(page), |
a54a407f | 1975 | NR_ISOLATED_ANON + page_lru, -HPAGE_PMD_NR); |
eb4489f6 MG |
1976 | |
1977 | goto out_unlock; | |
b32967ff MG |
1978 | } |
1979 | ||
2b4847e7 | 1980 | orig_entry = *pmd; |
10102459 | 1981 | entry = mk_huge_pmd(new_page, vma->vm_page_prot); |
2b4847e7 | 1982 | entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); |
b32967ff | 1983 | |
2b4847e7 MG |
1984 | /* |
1985 | * Clear the old entry under pagetable lock and establish the new PTE. | |
1986 | * Any parallel GUP will either observe the old page blocking on the | |
1987 | * page lock, block on the page table lock or observe the new page. | |
1988 | * The SetPageUptodate on the new page and page_add_new_anon_rmap | |
1989 | * guarantee the copy is visible before the pagetable update. | |
1990 | */ | |
f714f4f2 | 1991 | flush_cache_range(vma, mmun_start, mmun_end); |
d281ee61 | 1992 | page_add_anon_rmap(new_page, vma, mmun_start, true); |
8809aa2d | 1993 | pmdp_huge_clear_flush_notify(vma, mmun_start, pmd); |
f714f4f2 | 1994 | set_pmd_at(mm, mmun_start, pmd, entry); |
ce4a9cc5 | 1995 | update_mmu_cache_pmd(vma, address, &entry); |
2b4847e7 MG |
1996 | |
1997 | if (page_count(page) != 2) { | |
f714f4f2 | 1998 | set_pmd_at(mm, mmun_start, pmd, orig_entry); |
458aa76d | 1999 | flush_pmd_tlb_range(vma, mmun_start, mmun_end); |
34ee645e | 2000 | mmu_notifier_invalidate_range(mm, mmun_start, mmun_end); |
2b4847e7 | 2001 | update_mmu_cache_pmd(vma, address, &entry); |
d281ee61 | 2002 | page_remove_rmap(new_page, true); |
2b4847e7 MG |
2003 | goto fail_putback; |
2004 | } | |
2005 | ||
51afb12b | 2006 | mlock_migrate_page(new_page, page); |
d281ee61 | 2007 | page_remove_rmap(page, true); |
7cd12b4a | 2008 | set_page_owner_migrate_reason(new_page, MR_NUMA_MISPLACED); |
2b4847e7 | 2009 | |
c4088ebd | 2010 | spin_unlock(ptl); |
f714f4f2 | 2011 | mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end); |
b32967ff | 2012 | |
11de9927 MG |
2013 | /* Take an "isolate" reference and put new page on the LRU. */ |
2014 | get_page(new_page); | |
2015 | putback_lru_page(new_page); | |
2016 | ||
b32967ff MG |
2017 | unlock_page(new_page); |
2018 | unlock_page(page); | |
2019 | put_page(page); /* Drop the rmap reference */ | |
2020 | put_page(page); /* Drop the LRU isolation reference */ | |
2021 | ||
2022 | count_vm_events(PGMIGRATE_SUCCESS, HPAGE_PMD_NR); | |
2023 | count_vm_numa_events(NUMA_PAGE_MIGRATE, HPAGE_PMD_NR); | |
2024 | ||
599d0c95 | 2025 | mod_node_page_state(page_pgdat(page), |
b32967ff MG |
2026 | NR_ISOLATED_ANON + page_lru, |
2027 | -HPAGE_PMD_NR); | |
2028 | return isolated; | |
2029 | ||
340ef390 HD |
2030 | out_fail: |
2031 | count_vm_events(PGMIGRATE_FAIL, HPAGE_PMD_NR); | |
b32967ff | 2032 | out_dropref: |
2b4847e7 MG |
2033 | ptl = pmd_lock(mm, pmd); |
2034 | if (pmd_same(*pmd, entry)) { | |
4d942466 | 2035 | entry = pmd_modify(entry, vma->vm_page_prot); |
f714f4f2 | 2036 | set_pmd_at(mm, mmun_start, pmd, entry); |
2b4847e7 MG |
2037 | update_mmu_cache_pmd(vma, address, &entry); |
2038 | } | |
2039 | spin_unlock(ptl); | |
a54a407f | 2040 | |
eb4489f6 | 2041 | out_unlock: |
340ef390 | 2042 | unlock_page(page); |
b32967ff | 2043 | put_page(page); |
b32967ff MG |
2044 | return 0; |
2045 | } | |
7039e1db PZ |
2046 | #endif /* CONFIG_NUMA_BALANCING */ |
2047 | ||
2048 | #endif /* CONFIG_NUMA */ |