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15#include <linux/migrate.h>
16#include <linux/export.h>
17#include <linux/swap.h>
18#include <linux/swapops.h>
19#include <linux/pagemap.h>
20#include <linux/buffer_head.h>
21#include <linux/mm_inline.h>
22#include <linux/nsproxy.h>
23#include <linux/pagevec.h>
24#include <linux/ksm.h>
25#include <linux/rmap.h>
26#include <linux/topology.h>
27#include <linux/cpu.h>
28#include <linux/cpuset.h>
29#include <linux/writeback.h>
30#include <linux/mempolicy.h>
31#include <linux/vmalloc.h>
32#include <linux/security.h>
33#include <linux/backing-dev.h>
34#include <linux/syscalls.h>
35#include <linux/hugetlb.h>
36#include <linux/hugetlb_cgroup.h>
37#include <linux/gfp.h>
38#include <linux/balloon_compaction.h>
39#include <linux/mmu_notifier.h>
40#include <linux/page_idle.h>
41#include <linux/page_owner.h>
42
43#include <asm/tlbflush.h>
44
45#define CREATE_TRACE_POINTS
46#include <trace/events/migrate.h>
47
48#include "internal.h"
49
50
51
52
53
54
55int migrate_prep(void)
56{
57
58
59
60
61
62
63 lru_add_drain_all();
64
65 return 0;
66}
67
68
69int migrate_prep_local(void)
70{
71 lru_add_drain();
72
73 return 0;
74}
75
76
77
78
79
80
81
82
83
84void putback_movable_pages(struct list_head *l)
85{
86 struct page *page;
87 struct page *page2;
88
89 list_for_each_entry_safe(page, page2, l, lru) {
90 if (unlikely(PageHuge(page))) {
91 putback_active_hugepage(page);
92 continue;
93 }
94 list_del(&page->lru);
95 dec_zone_page_state(page, NR_ISOLATED_ANON +
96 page_is_file_cache(page));
97 if (unlikely(isolated_balloon_page(page)))
98 balloon_page_putback(page);
99 else
100 putback_lru_page(page);
101 }
102}
103
104
105
106
107static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,
108 unsigned long addr, void *old)
109{
110 struct mm_struct *mm = vma->vm_mm;
111 swp_entry_t entry;
112 pmd_t *pmd;
113 pte_t *ptep, pte;
114 spinlock_t *ptl;
115
116 if (unlikely(PageHuge(new))) {
117 ptep = huge_pte_offset(mm, addr);
118 if (!ptep)
119 goto out;
120 ptl = huge_pte_lockptr(hstate_vma(vma), mm, ptep);
121 } else {
122 pmd = mm_find_pmd(mm, addr);
123 if (!pmd)
124 goto out;
125
126 ptep = pte_offset_map(pmd, addr);
127
128
129
130
131
132
133 ptl = pte_lockptr(mm, pmd);
134 }
135
136 spin_lock(ptl);
137 pte = *ptep;
138 if (!is_swap_pte(pte))
139 goto unlock;
140
141 entry = pte_to_swp_entry(pte);
142
143 if (!is_migration_entry(entry) ||
144 migration_entry_to_page(entry) != old)
145 goto unlock;
146
147 get_page(new);
148 pte = pte_mkold(mk_pte(new, vma->vm_page_prot));
149 if (pte_swp_soft_dirty(*ptep))
150 pte = pte_mksoft_dirty(pte);
151
152
153 if (is_write_migration_entry(entry))
154 pte = maybe_mkwrite(pte, vma);
155
156#ifdef CONFIG_HUGETLB_PAGE
157 if (PageHuge(new)) {
158 pte = pte_mkhuge(pte);
159 pte = arch_make_huge_pte(pte, vma, new, 0);
160 }
161#endif
162 flush_dcache_page(new);
163 set_pte_at(mm, addr, ptep, pte);
164
165 if (PageHuge(new)) {
166 if (PageAnon(new))
167 hugepage_add_anon_rmap(new, vma, addr);
168 else
169 page_dup_rmap(new, true);
170 } else if (PageAnon(new))
171 page_add_anon_rmap(new, vma, addr, false);
172 else
173 page_add_file_rmap(new);
174
175 if (vma->vm_flags & VM_LOCKED && !PageTransCompound(new))
176 mlock_vma_page(new);
177
178
179 update_mmu_cache(vma, addr, ptep);
180unlock:
181 pte_unmap_unlock(ptep, ptl);
182out:
183 return SWAP_AGAIN;
184}
185
186
187
188
189
190void remove_migration_ptes(struct page *old, struct page *new, bool locked)
191{
192 struct rmap_walk_control rwc = {
193 .rmap_one = remove_migration_pte,
194 .arg = old,
195 };
196
197 if (locked)
198 rmap_walk_locked(new, &rwc);
199 else
200 rmap_walk(new, &rwc);
201}
202
203
204
205
206
207
208void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
209 spinlock_t *ptl)
210{
211 pte_t pte;
212 swp_entry_t entry;
213 struct page *page;
214
215 spin_lock(ptl);
216 pte = *ptep;
217 if (!is_swap_pte(pte))
218 goto out;
219
220 entry = pte_to_swp_entry(pte);
221 if (!is_migration_entry(entry))
222 goto out;
223
224 page = migration_entry_to_page(entry);
225
226
227
228
229
230
231
232
233 if (!get_page_unless_zero(page))
234 goto out;
235 pte_unmap_unlock(ptep, ptl);
236 wait_on_page_locked(page);
237 put_page(page);
238 return;
239out:
240 pte_unmap_unlock(ptep, ptl);
241}
242
243void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
244 unsigned long address)
245{
246 spinlock_t *ptl = pte_lockptr(mm, pmd);
247 pte_t *ptep = pte_offset_map(pmd, address);
248 __migration_entry_wait(mm, ptep, ptl);
249}
250
251void migration_entry_wait_huge(struct vm_area_struct *vma,
252 struct mm_struct *mm, pte_t *pte)
253{
254 spinlock_t *ptl = huge_pte_lockptr(hstate_vma(vma), mm, pte);
255 __migration_entry_wait(mm, pte, ptl);
256}
257
258#ifdef CONFIG_BLOCK
259
260static bool buffer_migrate_lock_buffers(struct buffer_head *head,
261 enum migrate_mode mode)
262{
263 struct buffer_head *bh = head;
264
265
266 if (mode != MIGRATE_ASYNC) {
267 do {
268 get_bh(bh);
269 lock_buffer(bh);
270 bh = bh->b_this_page;
271
272 } while (bh != head);
273
274 return true;
275 }
276
277
278 do {
279 get_bh(bh);
280 if (!trylock_buffer(bh)) {
281
282
283
284
285 struct buffer_head *failed_bh = bh;
286 put_bh(failed_bh);
287 bh = head;
288 while (bh != failed_bh) {
289 unlock_buffer(bh);
290 put_bh(bh);
291 bh = bh->b_this_page;
292 }
293 return false;
294 }
295
296 bh = bh->b_this_page;
297 } while (bh != head);
298 return true;
299}
300#else
301static inline bool buffer_migrate_lock_buffers(struct buffer_head *head,
302 enum migrate_mode mode)
303{
304 return true;
305}
306#endif
307
308
309
310
311
312
313
314
315
316int migrate_page_move_mapping(struct address_space *mapping,
317 struct page *newpage, struct page *page,
318 struct buffer_head *head, enum migrate_mode mode,
319 int extra_count)
320{
321 struct zone *oldzone, *newzone;
322 int dirty;
323 int expected_count = 1 + extra_count;
324 void **pslot;
325
326 if (!mapping) {
327
328 if (page_count(page) != expected_count)
329 return -EAGAIN;
330
331
332 newpage->index = page->index;
333 newpage->mapping = page->mapping;
334 if (PageSwapBacked(page))
335 SetPageSwapBacked(newpage);
336
337 return MIGRATEPAGE_SUCCESS;
338 }
339
340 oldzone = page_zone(page);
341 newzone = page_zone(newpage);
342
343 spin_lock_irq(&mapping->tree_lock);
344
345 pslot = radix_tree_lookup_slot(&mapping->page_tree,
346 page_index(page));
347
348 expected_count += 1 + page_has_private(page);
349 if (page_count(page) != expected_count ||
350 radix_tree_deref_slot_protected(pslot, &mapping->tree_lock) != page) {
351 spin_unlock_irq(&mapping->tree_lock);
352 return -EAGAIN;
353 }
354
355 if (!page_ref_freeze(page, expected_count)) {
356 spin_unlock_irq(&mapping->tree_lock);
357 return -EAGAIN;
358 }
359
360
361
362
363
364
365
366
367 if (mode == MIGRATE_ASYNC && head &&
368 !buffer_migrate_lock_buffers(head, mode)) {
369 page_ref_unfreeze(page, expected_count);
370 spin_unlock_irq(&mapping->tree_lock);
371 return -EAGAIN;
372 }
373
374
375
376
377
378 newpage->index = page->index;
379 newpage->mapping = page->mapping;
380 if (PageSwapBacked(page))
381 SetPageSwapBacked(newpage);
382
383 get_page(newpage);
384 if (PageSwapCache(page)) {
385 SetPageSwapCache(newpage);
386 set_page_private(newpage, page_private(page));
387 }
388
389
390 dirty = PageDirty(page);
391 if (dirty) {
392 ClearPageDirty(page);
393 SetPageDirty(newpage);
394 }
395
396 radix_tree_replace_slot(pslot, newpage);
397
398
399
400
401
402
403 page_ref_unfreeze(page, expected_count - 1);
404
405 spin_unlock(&mapping->tree_lock);
406
407
408
409
410
411
412
413
414
415
416
417
418 if (newzone != oldzone) {
419 __dec_zone_state(oldzone, NR_FILE_PAGES);
420 __inc_zone_state(newzone, NR_FILE_PAGES);
421 if (PageSwapBacked(page) && !PageSwapCache(page)) {
422 __dec_zone_state(oldzone, NR_SHMEM);
423 __inc_zone_state(newzone, NR_SHMEM);
424 }
425 if (dirty && mapping_cap_account_dirty(mapping)) {
426 __dec_zone_state(oldzone, NR_FILE_DIRTY);
427 __inc_zone_state(newzone, NR_FILE_DIRTY);
428 }
429 }
430 local_irq_enable();
431
432 return MIGRATEPAGE_SUCCESS;
433}
434
435
436
437
438
439int migrate_huge_page_move_mapping(struct address_space *mapping,
440 struct page *newpage, struct page *page)
441{
442 int expected_count;
443 void **pslot;
444
445 spin_lock_irq(&mapping->tree_lock);
446
447 pslot = radix_tree_lookup_slot(&mapping->page_tree,
448 page_index(page));
449
450 expected_count = 2 + page_has_private(page);
451 if (page_count(page) != expected_count ||
452 radix_tree_deref_slot_protected(pslot, &mapping->tree_lock) != page) {
453 spin_unlock_irq(&mapping->tree_lock);
454 return -EAGAIN;
455 }
456
457 if (!page_ref_freeze(page, expected_count)) {
458 spin_unlock_irq(&mapping->tree_lock);
459 return -EAGAIN;
460 }
461
462 newpage->index = page->index;
463 newpage->mapping = page->mapping;
464
465 get_page(newpage);
466
467 radix_tree_replace_slot(pslot, newpage);
468
469 page_ref_unfreeze(page, expected_count - 1);
470
471 spin_unlock_irq(&mapping->tree_lock);
472
473 return MIGRATEPAGE_SUCCESS;
474}
475
476
477
478
479
480
481static void __copy_gigantic_page(struct page *dst, struct page *src,
482 int nr_pages)
483{
484 int i;
485 struct page *dst_base = dst;
486 struct page *src_base = src;
487
488 for (i = 0; i < nr_pages; ) {
489 cond_resched();
490 copy_highpage(dst, src);
491
492 i++;
493 dst = mem_map_next(dst, dst_base, i);
494 src = mem_map_next(src, src_base, i);
495 }
496}
497
498static void copy_huge_page(struct page *dst, struct page *src)
499{
500 int i;
501 int nr_pages;
502
503 if (PageHuge(src)) {
504
505 struct hstate *h = page_hstate(src);
506 nr_pages = pages_per_huge_page(h);
507
508 if (unlikely(nr_pages > MAX_ORDER_NR_PAGES)) {
509 __copy_gigantic_page(dst, src, nr_pages);
510 return;
511 }
512 } else {
513
514 BUG_ON(!PageTransHuge(src));
515 nr_pages = hpage_nr_pages(src);
516 }
517
518 for (i = 0; i < nr_pages; i++) {
519 cond_resched();
520 copy_highpage(dst + i, src + i);
521 }
522}
523
524
525
526
527void migrate_page_copy(struct page *newpage, struct page *page)
528{
529 int cpupid;
530
531 if (PageHuge(page) || PageTransHuge(page))
532 copy_huge_page(newpage, page);
533 else
534 copy_highpage(newpage, page);
535
536 if (PageError(page))
537 SetPageError(newpage);
538 if (PageReferenced(page))
539 SetPageReferenced(newpage);
540 if (PageUptodate(page))
541 SetPageUptodate(newpage);
542 if (TestClearPageActive(page)) {
543 VM_BUG_ON_PAGE(PageUnevictable(page), page);
544 SetPageActive(newpage);
545 } else if (TestClearPageUnevictable(page))
546 SetPageUnevictable(newpage);
547 if (PageChecked(page))
548 SetPageChecked(newpage);
549 if (PageMappedToDisk(page))
550 SetPageMappedToDisk(newpage);
551
552
553 if (PageDirty(page))
554 SetPageDirty(newpage);
555
556 if (page_is_young(page))
557 set_page_young(newpage);
558 if (page_is_idle(page))
559 set_page_idle(newpage);
560
561
562
563
564
565 cpupid = page_cpupid_xchg_last(page, -1);
566 page_cpupid_xchg_last(newpage, cpupid);
567
568 ksm_migrate_page(newpage, page);
569
570
571
572
573 if (PageSwapCache(page))
574 ClearPageSwapCache(page);
575 ClearPagePrivate(page);
576 set_page_private(page, 0);
577
578
579
580
581
582 if (PageWriteback(newpage))
583 end_page_writeback(newpage);
584
585 copy_page_owner(page, newpage);
586
587 mem_cgroup_migrate(page, newpage);
588}
589
590
591
592
593
594
595
596
597
598
599
600int migrate_page(struct address_space *mapping,
601 struct page *newpage, struct page *page,
602 enum migrate_mode mode)
603{
604 int rc;
605
606 BUG_ON(PageWriteback(page));
607
608 rc = migrate_page_move_mapping(mapping, newpage, page, NULL, mode, 0);
609
610 if (rc != MIGRATEPAGE_SUCCESS)
611 return rc;
612
613 migrate_page_copy(newpage, page);
614 return MIGRATEPAGE_SUCCESS;
615}
616EXPORT_SYMBOL(migrate_page);
617
618#ifdef CONFIG_BLOCK
619
620
621
622
623
624int buffer_migrate_page(struct address_space *mapping,
625 struct page *newpage, struct page *page, enum migrate_mode mode)
626{
627 struct buffer_head *bh, *head;
628 int rc;
629
630 if (!page_has_buffers(page))
631 return migrate_page(mapping, newpage, page, mode);
632
633 head = page_buffers(page);
634
635 rc = migrate_page_move_mapping(mapping, newpage, page, head, mode, 0);
636
637 if (rc != MIGRATEPAGE_SUCCESS)
638 return rc;
639
640
641
642
643
644
645 if (mode != MIGRATE_ASYNC)
646 BUG_ON(!buffer_migrate_lock_buffers(head, mode));
647
648 ClearPagePrivate(page);
649 set_page_private(newpage, page_private(page));
650 set_page_private(page, 0);
651 put_page(page);
652 get_page(newpage);
653
654 bh = head;
655 do {
656 set_bh_page(bh, newpage, bh_offset(bh));
657 bh = bh->b_this_page;
658
659 } while (bh != head);
660
661 SetPagePrivate(newpage);
662
663 migrate_page_copy(newpage, page);
664
665 bh = head;
666 do {
667 unlock_buffer(bh);
668 put_bh(bh);
669 bh = bh->b_this_page;
670
671 } while (bh != head);
672
673 return MIGRATEPAGE_SUCCESS;
674}
675EXPORT_SYMBOL(buffer_migrate_page);
676#endif
677
678
679
680
681static int writeout(struct address_space *mapping, struct page *page)
682{
683 struct writeback_control wbc = {
684 .sync_mode = WB_SYNC_NONE,
685 .nr_to_write = 1,
686 .range_start = 0,
687 .range_end = LLONG_MAX,
688 .for_reclaim = 1
689 };
690 int rc;
691
692 if (!mapping->a_ops->writepage)
693
694 return -EINVAL;
695
696 if (!clear_page_dirty_for_io(page))
697
698 return -EAGAIN;
699
700
701
702
703
704
705
706
707
708 remove_migration_ptes(page, page, false);
709
710 rc = mapping->a_ops->writepage(page, &wbc);
711
712 if (rc != AOP_WRITEPAGE_ACTIVATE)
713
714 lock_page(page);
715
716 return (rc < 0) ? -EIO : -EAGAIN;
717}
718
719
720
721
722static int fallback_migrate_page(struct address_space *mapping,
723 struct page *newpage, struct page *page, enum migrate_mode mode)
724{
725 if (PageDirty(page)) {
726
727 if (mode != MIGRATE_SYNC)
728 return -EBUSY;
729 return writeout(mapping, page);
730 }
731
732
733
734
735
736 if (page_has_private(page) &&
737 !try_to_release_page(page, GFP_KERNEL))
738 return -EAGAIN;
739
740 return migrate_page(mapping, newpage, page, mode);
741}
742
743
744
745
746
747
748
749
750
751
752
753
754static int move_to_new_page(struct page *newpage, struct page *page,
755 enum migrate_mode mode)
756{
757 struct address_space *mapping;
758 int rc;
759
760 VM_BUG_ON_PAGE(!PageLocked(page), page);
761 VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
762
763 mapping = page_mapping(page);
764 if (!mapping)
765 rc = migrate_page(mapping, newpage, page, mode);
766 else if (mapping->a_ops->migratepage)
767
768
769
770
771
772
773 rc = mapping->a_ops->migratepage(mapping, newpage, page, mode);
774 else
775 rc = fallback_migrate_page(mapping, newpage, page, mode);
776
777
778
779
780
781 if (rc == MIGRATEPAGE_SUCCESS) {
782 if (!PageAnon(page))
783 page->mapping = NULL;
784 }
785 return rc;
786}
787
788static int __unmap_and_move(struct page *page, struct page *newpage,
789 int force, enum migrate_mode mode)
790{
791 int rc = -EAGAIN;
792 int page_was_mapped = 0;
793 struct anon_vma *anon_vma = NULL;
794
795 if (!trylock_page(page)) {
796 if (!force || mode == MIGRATE_ASYNC)
797 goto out;
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812 if (current->flags & PF_MEMALLOC)
813 goto out;
814
815 lock_page(page);
816 }
817
818 if (PageWriteback(page)) {
819
820
821
822
823
824
825 if (mode != MIGRATE_SYNC) {
826 rc = -EBUSY;
827 goto out_unlock;
828 }
829 if (!force)
830 goto out_unlock;
831 wait_on_page_writeback(page);
832 }
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848 if (PageAnon(page) && !PageKsm(page))
849 anon_vma = page_get_anon_vma(page);
850
851
852
853
854
855
856
857
858
859 if (unlikely(!trylock_page(newpage)))
860 goto out_unlock;
861
862 if (unlikely(isolated_balloon_page(page))) {
863
864
865
866
867
868
869
870 rc = balloon_page_migrate(newpage, page, mode);
871 goto out_unlock_both;
872 }
873
874
875
876
877
878
879
880
881
882
883
884
885
886 if (!page->mapping) {
887 VM_BUG_ON_PAGE(PageAnon(page), page);
888 if (page_has_private(page)) {
889 try_to_free_buffers(page);
890 goto out_unlock_both;
891 }
892 } else if (page_mapped(page)) {
893
894 VM_BUG_ON_PAGE(PageAnon(page) && !PageKsm(page) && !anon_vma,
895 page);
896 try_to_unmap(page,
897 TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS);
898 page_was_mapped = 1;
899 }
900
901 if (!page_mapped(page))
902 rc = move_to_new_page(newpage, page, mode);
903
904 if (page_was_mapped)
905 remove_migration_ptes(page,
906 rc == MIGRATEPAGE_SUCCESS ? newpage : page, false);
907
908out_unlock_both:
909 unlock_page(newpage);
910out_unlock:
911
912 if (anon_vma)
913 put_anon_vma(anon_vma);
914 unlock_page(page);
915out:
916 return rc;
917}
918
919
920
921
922
923#if (GCC_VERSION >= 40700 && GCC_VERSION < 40900) && defined(CONFIG_ARM)
924#define ICE_noinline noinline
925#else
926#define ICE_noinline
927#endif
928
929
930
931
932
933static ICE_noinline int unmap_and_move(new_page_t get_new_page,
934 free_page_t put_new_page,
935 unsigned long private, struct page *page,
936 int force, enum migrate_mode mode,
937 enum migrate_reason reason)
938{
939 int rc = MIGRATEPAGE_SUCCESS;
940 int *result = NULL;
941 struct page *newpage;
942
943 newpage = get_new_page(page, private, &result);
944 if (!newpage)
945 return -ENOMEM;
946
947 if (page_count(page) == 1) {
948
949 goto out;
950 }
951
952 if (unlikely(PageTransHuge(page))) {
953 lock_page(page);
954 rc = split_huge_page(page);
955 unlock_page(page);
956 if (rc)
957 goto out;
958 }
959
960 rc = __unmap_and_move(page, newpage, force, mode);
961 if (rc == MIGRATEPAGE_SUCCESS) {
962 put_new_page = NULL;
963 set_page_owner_migrate_reason(newpage, reason);
964 }
965
966out:
967 if (rc != -EAGAIN) {
968
969
970
971
972
973
974 list_del(&page->lru);
975 dec_zone_page_state(page, NR_ISOLATED_ANON +
976 page_is_file_cache(page));
977
978 if (reason == MR_MEMORY_FAILURE && rc == MIGRATEPAGE_SUCCESS) {
979
980
981
982
983
984
985 put_page(page);
986 if (!test_set_page_hwpoison(page))
987 num_poisoned_pages_inc();
988 } else
989 putback_lru_page(page);
990 }
991
992
993
994
995
996
997 if (put_new_page)
998 put_new_page(newpage, private);
999 else if (unlikely(__is_movable_balloon_page(newpage))) {
1000
1001 put_page(newpage);
1002 } else
1003 putback_lru_page(newpage);
1004
1005 if (result) {
1006 if (rc)
1007 *result = rc;
1008 else
1009 *result = page_to_nid(newpage);
1010 }
1011 return rc;
1012}
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032static int unmap_and_move_huge_page(new_page_t get_new_page,
1033 free_page_t put_new_page, unsigned long private,
1034 struct page *hpage, int force,
1035 enum migrate_mode mode, int reason)
1036{
1037 int rc = -EAGAIN;
1038 int *result = NULL;
1039 int page_was_mapped = 0;
1040 struct page *new_hpage;
1041 struct anon_vma *anon_vma = NULL;
1042
1043
1044
1045
1046
1047
1048
1049
1050 if (!hugepage_migration_supported(page_hstate(hpage))) {
1051 putback_active_hugepage(hpage);
1052 return -ENOSYS;
1053 }
1054
1055 new_hpage = get_new_page(hpage, private, &result);
1056 if (!new_hpage)
1057 return -ENOMEM;
1058
1059 if (!trylock_page(hpage)) {
1060 if (!force || mode != MIGRATE_SYNC)
1061 goto out;
1062 lock_page(hpage);
1063 }
1064
1065 if (PageAnon(hpage))
1066 anon_vma = page_get_anon_vma(hpage);
1067
1068 if (unlikely(!trylock_page(new_hpage)))
1069 goto put_anon;
1070
1071 if (page_mapped(hpage)) {
1072 try_to_unmap(hpage,
1073 TTU_MIGRATION|TTU_IGNORE_MLOCK|TTU_IGNORE_ACCESS);
1074 page_was_mapped = 1;
1075 }
1076
1077 if (!page_mapped(hpage))
1078 rc = move_to_new_page(new_hpage, hpage, mode);
1079
1080 if (page_was_mapped)
1081 remove_migration_ptes(hpage,
1082 rc == MIGRATEPAGE_SUCCESS ? new_hpage : hpage, false);
1083
1084 unlock_page(new_hpage);
1085
1086put_anon:
1087 if (anon_vma)
1088 put_anon_vma(anon_vma);
1089
1090 if (rc == MIGRATEPAGE_SUCCESS) {
1091 hugetlb_cgroup_migrate(hpage, new_hpage);
1092 put_new_page = NULL;
1093 set_page_owner_migrate_reason(new_hpage, reason);
1094 }
1095
1096 unlock_page(hpage);
1097out:
1098 if (rc != -EAGAIN)
1099 putback_active_hugepage(hpage);
1100
1101
1102
1103
1104
1105
1106 if (put_new_page)
1107 put_new_page(new_hpage, private);
1108 else
1109 putback_active_hugepage(new_hpage);
1110
1111 if (result) {
1112 if (rc)
1113 *result = rc;
1114 else
1115 *result = page_to_nid(new_hpage);
1116 }
1117 return rc;
1118}
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141int migrate_pages(struct list_head *from, new_page_t get_new_page,
1142 free_page_t put_new_page, unsigned long private,
1143 enum migrate_mode mode, int reason)
1144{
1145 int retry = 1;
1146 int nr_failed = 0;
1147 int nr_succeeded = 0;
1148 int pass = 0;
1149 struct page *page;
1150 struct page *page2;
1151 int swapwrite = current->flags & PF_SWAPWRITE;
1152 int rc;
1153
1154 if (!swapwrite)
1155 current->flags |= PF_SWAPWRITE;
1156
1157 for(pass = 0; pass < 10 && retry; pass++) {
1158 retry = 0;
1159
1160 list_for_each_entry_safe(page, page2, from, lru) {
1161 cond_resched();
1162
1163 if (PageHuge(page))
1164 rc = unmap_and_move_huge_page(get_new_page,
1165 put_new_page, private, page,
1166 pass > 2, mode, reason);
1167 else
1168 rc = unmap_and_move(get_new_page, put_new_page,
1169 private, page, pass > 2, mode,
1170 reason);
1171
1172 switch(rc) {
1173 case -ENOMEM:
1174 goto out;
1175 case -EAGAIN:
1176 retry++;
1177 break;
1178 case MIGRATEPAGE_SUCCESS:
1179 nr_succeeded++;
1180 break;
1181 default:
1182
1183
1184
1185
1186
1187
1188 nr_failed++;
1189 break;
1190 }
1191 }
1192 }
1193 nr_failed += retry;
1194 rc = nr_failed;
1195out:
1196 if (nr_succeeded)
1197 count_vm_events(PGMIGRATE_SUCCESS, nr_succeeded);
1198 if (nr_failed)
1199 count_vm_events(PGMIGRATE_FAIL, nr_failed);
1200 trace_mm_migrate_pages(nr_succeeded, nr_failed, mode, reason);
1201
1202 if (!swapwrite)
1203 current->flags &= ~PF_SWAPWRITE;
1204
1205 return rc;
1206}
1207
1208#ifdef CONFIG_NUMA
1209
1210
1211
1212struct page_to_node {
1213 unsigned long addr;
1214 struct page *page;
1215 int node;
1216 int status;
1217};
1218
1219static struct page *new_page_node(struct page *p, unsigned long private,
1220 int **result)
1221{
1222 struct page_to_node *pm = (struct page_to_node *)private;
1223
1224 while (pm->node != MAX_NUMNODES && pm->page != p)
1225 pm++;
1226
1227 if (pm->node == MAX_NUMNODES)
1228 return NULL;
1229
1230 *result = &pm->status;
1231
1232 if (PageHuge(p))
1233 return alloc_huge_page_node(page_hstate(compound_head(p)),
1234 pm->node);
1235 else
1236 return __alloc_pages_node(pm->node,
1237 GFP_HIGHUSER_MOVABLE | __GFP_THISNODE, 0);
1238}
1239
1240
1241
1242
1243
1244
1245
1246static int do_move_page_to_node_array(struct mm_struct *mm,
1247 struct page_to_node *pm,
1248 int migrate_all)
1249{
1250 int err;
1251 struct page_to_node *pp;
1252 LIST_HEAD(pagelist);
1253
1254 down_read(&mm->mmap_sem);
1255
1256
1257
1258
1259 for (pp = pm; pp->node != MAX_NUMNODES; pp++) {
1260 struct vm_area_struct *vma;
1261 struct page *page;
1262
1263 err = -EFAULT;
1264 vma = find_vma(mm, pp->addr);
1265 if (!vma || pp->addr < vma->vm_start || !vma_migratable(vma))
1266 goto set_status;
1267
1268
1269 page = follow_page(vma, pp->addr,
1270 FOLL_GET | FOLL_SPLIT | FOLL_DUMP);
1271
1272 err = PTR_ERR(page);
1273 if (IS_ERR(page))
1274 goto set_status;
1275
1276 err = -ENOENT;
1277 if (!page)
1278 goto set_status;
1279
1280 pp->page = page;
1281 err = page_to_nid(page);
1282
1283 if (err == pp->node)
1284
1285
1286
1287 goto put_and_set;
1288
1289 err = -EACCES;
1290 if (page_mapcount(page) > 1 &&
1291 !migrate_all)
1292 goto put_and_set;
1293
1294 if (PageHuge(page)) {
1295 if (PageHead(page))
1296 isolate_huge_page(page, &pagelist);
1297 goto put_and_set;
1298 }
1299
1300 err = isolate_lru_page(page);
1301 if (!err) {
1302 list_add_tail(&page->lru, &pagelist);
1303 inc_zone_page_state(page, NR_ISOLATED_ANON +
1304 page_is_file_cache(page));
1305 }
1306put_and_set:
1307
1308
1309
1310
1311
1312 put_page(page);
1313set_status:
1314 pp->status = err;
1315 }
1316
1317 err = 0;
1318 if (!list_empty(&pagelist)) {
1319 err = migrate_pages(&pagelist, new_page_node, NULL,
1320 (unsigned long)pm, MIGRATE_SYNC, MR_SYSCALL);
1321 if (err)
1322 putback_movable_pages(&pagelist);
1323 }
1324
1325 up_read(&mm->mmap_sem);
1326 return err;
1327}
1328
1329
1330
1331
1332
1333static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes,
1334 unsigned long nr_pages,
1335 const void __user * __user *pages,
1336 const int __user *nodes,
1337 int __user *status, int flags)
1338{
1339 struct page_to_node *pm;
1340 unsigned long chunk_nr_pages;
1341 unsigned long chunk_start;
1342 int err;
1343
1344 err = -ENOMEM;
1345 pm = (struct page_to_node *)__get_free_page(GFP_KERNEL);
1346 if (!pm)
1347 goto out;
1348
1349 migrate_prep();
1350
1351
1352
1353
1354
1355 chunk_nr_pages = (PAGE_SIZE / sizeof(struct page_to_node)) - 1;
1356
1357 for (chunk_start = 0;
1358 chunk_start < nr_pages;
1359 chunk_start += chunk_nr_pages) {
1360 int j;
1361
1362 if (chunk_start + chunk_nr_pages > nr_pages)
1363 chunk_nr_pages = nr_pages - chunk_start;
1364
1365
1366 for (j = 0; j < chunk_nr_pages; j++) {
1367 const void __user *p;
1368 int node;
1369
1370 err = -EFAULT;
1371 if (get_user(p, pages + j + chunk_start))
1372 goto out_pm;
1373 pm[j].addr = (unsigned long) p;
1374
1375 if (get_user(node, nodes + j + chunk_start))
1376 goto out_pm;
1377
1378 err = -ENODEV;
1379 if (node < 0 || node >= MAX_NUMNODES)
1380 goto out_pm;
1381
1382 if (!node_state(node, N_MEMORY))
1383 goto out_pm;
1384
1385 err = -EACCES;
1386 if (!node_isset(node, task_nodes))
1387 goto out_pm;
1388
1389 pm[j].node = node;
1390 }
1391
1392
1393 pm[chunk_nr_pages].node = MAX_NUMNODES;
1394
1395
1396 err = do_move_page_to_node_array(mm, pm,
1397 flags & MPOL_MF_MOVE_ALL);
1398 if (err < 0)
1399 goto out_pm;
1400
1401
1402 for (j = 0; j < chunk_nr_pages; j++)
1403 if (put_user(pm[j].status, status + j + chunk_start)) {
1404 err = -EFAULT;
1405 goto out_pm;
1406 }
1407 }
1408 err = 0;
1409
1410out_pm:
1411 free_page((unsigned long)pm);
1412out:
1413 return err;
1414}
1415
1416
1417
1418
1419static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages,
1420 const void __user **pages, int *status)
1421{
1422 unsigned long i;
1423
1424 down_read(&mm->mmap_sem);
1425
1426 for (i = 0; i < nr_pages; i++) {
1427 unsigned long addr = (unsigned long)(*pages);
1428 struct vm_area_struct *vma;
1429 struct page *page;
1430 int err = -EFAULT;
1431
1432 vma = find_vma(mm, addr);
1433 if (!vma || addr < vma->vm_start)
1434 goto set_status;
1435
1436
1437 page = follow_page(vma, addr, FOLL_DUMP);
1438
1439 err = PTR_ERR(page);
1440 if (IS_ERR(page))
1441 goto set_status;
1442
1443 err = page ? page_to_nid(page) : -ENOENT;
1444set_status:
1445 *status = err;
1446
1447 pages++;
1448 status++;
1449 }
1450
1451 up_read(&mm->mmap_sem);
1452}
1453
1454
1455
1456
1457
1458static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages,
1459 const void __user * __user *pages,
1460 int __user *status)
1461{
1462#define DO_PAGES_STAT_CHUNK_NR 16
1463 const void __user *chunk_pages[DO_PAGES_STAT_CHUNK_NR];
1464 int chunk_status[DO_PAGES_STAT_CHUNK_NR];
1465
1466 while (nr_pages) {
1467 unsigned long chunk_nr;
1468
1469 chunk_nr = nr_pages;
1470 if (chunk_nr > DO_PAGES_STAT_CHUNK_NR)
1471 chunk_nr = DO_PAGES_STAT_CHUNK_NR;
1472
1473 if (copy_from_user(chunk_pages, pages, chunk_nr * sizeof(*chunk_pages)))
1474 break;
1475
1476 do_pages_stat_array(mm, chunk_nr, chunk_pages, chunk_status);
1477
1478 if (copy_to_user(status, chunk_status, chunk_nr * sizeof(*status)))
1479 break;
1480
1481 pages += chunk_nr;
1482 status += chunk_nr;
1483 nr_pages -= chunk_nr;
1484 }
1485 return nr_pages ? -EFAULT : 0;
1486}
1487
1488
1489
1490
1491
1492SYSCALL_DEFINE6(move_pages, pid_t, pid, unsigned long, nr_pages,
1493 const void __user * __user *, pages,
1494 const int __user *, nodes,
1495 int __user *, status, int, flags)
1496{
1497 const struct cred *cred = current_cred(), *tcred;
1498 struct task_struct *task;
1499 struct mm_struct *mm;
1500 int err;
1501 nodemask_t task_nodes;
1502
1503
1504 if (flags & ~(MPOL_MF_MOVE|MPOL_MF_MOVE_ALL))
1505 return -EINVAL;
1506
1507 if ((flags & MPOL_MF_MOVE_ALL) && !capable(CAP_SYS_NICE))
1508 return -EPERM;
1509
1510
1511 rcu_read_lock();
1512 task = pid ? find_task_by_vpid(pid) : current;
1513 if (!task) {
1514 rcu_read_unlock();
1515 return -ESRCH;
1516 }
1517 get_task_struct(task);
1518
1519
1520
1521
1522
1523
1524
1525 tcred = __task_cred(task);
1526 if (!uid_eq(cred->euid, tcred->suid) && !uid_eq(cred->euid, tcred->uid) &&
1527 !uid_eq(cred->uid, tcred->suid) && !uid_eq(cred->uid, tcred->uid) &&
1528 !capable(CAP_SYS_NICE)) {
1529 rcu_read_unlock();
1530 err = -EPERM;
1531 goto out;
1532 }
1533 rcu_read_unlock();
1534
1535 err = security_task_movememory(task);
1536 if (err)
1537 goto out;
1538
1539 task_nodes = cpuset_mems_allowed(task);
1540 mm = get_task_mm(task);
1541 put_task_struct(task);
1542
1543 if (!mm)
1544 return -EINVAL;
1545
1546 if (nodes)
1547 err = do_pages_move(mm, task_nodes, nr_pages, pages,
1548 nodes, status, flags);
1549 else
1550 err = do_pages_stat(mm, nr_pages, pages, status);
1551
1552 mmput(mm);
1553 return err;
1554
1555out:
1556 put_task_struct(task);
1557 return err;
1558}
1559
1560#ifdef CONFIG_NUMA_BALANCING
1561
1562
1563
1564
1565static bool migrate_balanced_pgdat(struct pglist_data *pgdat,
1566 unsigned long nr_migrate_pages)
1567{
1568 int z;
1569 for (z = pgdat->nr_zones - 1; z >= 0; z--) {
1570 struct zone *zone = pgdat->node_zones + z;
1571
1572 if (!populated_zone(zone))
1573 continue;
1574
1575 if (!zone_reclaimable(zone))
1576 continue;
1577
1578
1579 if (!zone_watermark_ok(zone, 0,
1580 high_wmark_pages(zone) +
1581 nr_migrate_pages,
1582 0, 0))
1583 continue;
1584 return true;
1585 }
1586 return false;
1587}
1588
1589static struct page *alloc_misplaced_dst_page(struct page *page,
1590 unsigned long data,
1591 int **result)
1592{
1593 int nid = (int) data;
1594 struct page *newpage;
1595
1596 newpage = __alloc_pages_node(nid,
1597 (GFP_HIGHUSER_MOVABLE |
1598 __GFP_THISNODE | __GFP_NOMEMALLOC |
1599 __GFP_NORETRY | __GFP_NOWARN) &
1600 ~__GFP_RECLAIM, 0);
1601
1602 return newpage;
1603}
1604
1605
1606
1607
1608
1609
1610static unsigned int migrate_interval_millisecs __read_mostly = 100;
1611static unsigned int ratelimit_pages __read_mostly = 128 << (20 - PAGE_SHIFT);
1612
1613
1614static bool numamigrate_update_ratelimit(pg_data_t *pgdat,
1615 unsigned long nr_pages)
1616{
1617
1618
1619
1620
1621
1622 if (time_after(jiffies, pgdat->numabalancing_migrate_next_window)) {
1623 spin_lock(&pgdat->numabalancing_migrate_lock);
1624 pgdat->numabalancing_migrate_nr_pages = 0;
1625 pgdat->numabalancing_migrate_next_window = jiffies +
1626 msecs_to_jiffies(migrate_interval_millisecs);
1627 spin_unlock(&pgdat->numabalancing_migrate_lock);
1628 }
1629 if (pgdat->numabalancing_migrate_nr_pages > ratelimit_pages) {
1630 trace_mm_numa_migrate_ratelimit(current, pgdat->node_id,
1631 nr_pages);
1632 return true;
1633 }
1634
1635
1636
1637
1638
1639
1640
1641 pgdat->numabalancing_migrate_nr_pages += nr_pages;
1642 return false;
1643}
1644
1645static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
1646{
1647 int page_lru;
1648
1649 VM_BUG_ON_PAGE(compound_order(page) && !PageTransHuge(page), page);
1650
1651
1652 if (!migrate_balanced_pgdat(pgdat, 1UL << compound_order(page)))
1653 return 0;
1654
1655 if (isolate_lru_page(page))
1656 return 0;
1657
1658
1659
1660
1661
1662
1663
1664
1665 if (PageTransHuge(page) && page_count(page) != 3) {
1666 putback_lru_page(page);
1667 return 0;
1668 }
1669
1670 page_lru = page_is_file_cache(page);
1671 mod_zone_page_state(page_zone(page), NR_ISOLATED_ANON + page_lru,
1672 hpage_nr_pages(page));
1673
1674
1675
1676
1677
1678
1679 put_page(page);
1680 return 1;
1681}
1682
1683bool pmd_trans_migrating(pmd_t pmd)
1684{
1685 struct page *page = pmd_page(pmd);
1686 return PageLocked(page);
1687}
1688
1689
1690
1691
1692
1693
1694int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
1695 int node)
1696{
1697 pg_data_t *pgdat = NODE_DATA(node);
1698 int isolated;
1699 int nr_remaining;
1700 LIST_HEAD(migratepages);
1701
1702
1703
1704
1705
1706 if (page_mapcount(page) != 1 && page_is_file_cache(page) &&
1707 (vma->vm_flags & VM_EXEC))
1708 goto out;
1709
1710
1711
1712
1713
1714
1715 if (numamigrate_update_ratelimit(pgdat, 1))
1716 goto out;
1717
1718 isolated = numamigrate_isolate_page(pgdat, page);
1719 if (!isolated)
1720 goto out;
1721
1722 list_add(&page->lru, &migratepages);
1723 nr_remaining = migrate_pages(&migratepages, alloc_misplaced_dst_page,
1724 NULL, node, MIGRATE_ASYNC,
1725 MR_NUMA_MISPLACED);
1726 if (nr_remaining) {
1727 if (!list_empty(&migratepages)) {
1728 list_del(&page->lru);
1729 dec_zone_page_state(page, NR_ISOLATED_ANON +
1730 page_is_file_cache(page));
1731 putback_lru_page(page);
1732 }
1733 isolated = 0;
1734 } else
1735 count_vm_numa_event(NUMA_PAGE_MIGRATE);
1736 BUG_ON(!list_empty(&migratepages));
1737 return isolated;
1738
1739out:
1740 put_page(page);
1741 return 0;
1742}
1743#endif
1744
1745#if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
1746
1747
1748
1749
1750int migrate_misplaced_transhuge_page(struct mm_struct *mm,
1751 struct vm_area_struct *vma,
1752 pmd_t *pmd, pmd_t entry,
1753 unsigned long address,
1754 struct page *page, int node)
1755{
1756 spinlock_t *ptl;
1757 pg_data_t *pgdat = NODE_DATA(node);
1758 int isolated = 0;
1759 struct page *new_page = NULL;
1760 int page_lru = page_is_file_cache(page);
1761 unsigned long mmun_start = address & HPAGE_PMD_MASK;
1762 unsigned long mmun_end = mmun_start + HPAGE_PMD_SIZE;
1763 pmd_t orig_entry;
1764
1765
1766
1767
1768
1769
1770 if (numamigrate_update_ratelimit(pgdat, HPAGE_PMD_NR))
1771 goto out_dropref;
1772
1773 new_page = alloc_pages_node(node,
1774 (GFP_TRANSHUGE | __GFP_THISNODE) & ~__GFP_RECLAIM,
1775 HPAGE_PMD_ORDER);
1776 if (!new_page)
1777 goto out_fail;
1778 prep_transhuge_page(new_page);
1779
1780 isolated = numamigrate_isolate_page(pgdat, page);
1781 if (!isolated) {
1782 put_page(new_page);
1783 goto out_fail;
1784 }
1785
1786
1787
1788
1789 if (mm_tlb_flush_pending(mm))
1790 flush_tlb_range(vma, mmun_start, mmun_end);
1791
1792
1793 __SetPageLocked(new_page);
1794 SetPageSwapBacked(new_page);
1795
1796
1797 new_page->mapping = page->mapping;
1798 new_page->index = page->index;
1799 migrate_page_copy(new_page, page);
1800 WARN_ON(PageLRU(new_page));
1801
1802
1803 mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
1804 ptl = pmd_lock(mm, pmd);
1805 if (unlikely(!pmd_same(*pmd, entry) || page_count(page) != 2)) {
1806fail_putback:
1807 spin_unlock(ptl);
1808 mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
1809
1810
1811 if (TestClearPageActive(new_page))
1812 SetPageActive(page);
1813 if (TestClearPageUnevictable(new_page))
1814 SetPageUnevictable(page);
1815
1816 unlock_page(new_page);
1817 put_page(new_page);
1818
1819
1820 get_page(page);
1821 putback_lru_page(page);
1822 mod_zone_page_state(page_zone(page),
1823 NR_ISOLATED_ANON + page_lru, -HPAGE_PMD_NR);
1824
1825 goto out_unlock;
1826 }
1827
1828 orig_entry = *pmd;
1829 entry = mk_pmd(new_page, vma->vm_page_prot);
1830 entry = pmd_mkhuge(entry);
1831 entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
1832
1833
1834
1835
1836
1837
1838
1839
1840 flush_cache_range(vma, mmun_start, mmun_end);
1841 page_add_anon_rmap(new_page, vma, mmun_start, true);
1842 pmdp_huge_clear_flush_notify(vma, mmun_start, pmd);
1843 set_pmd_at(mm, mmun_start, pmd, entry);
1844 update_mmu_cache_pmd(vma, address, &entry);
1845
1846 if (page_count(page) != 2) {
1847 set_pmd_at(mm, mmun_start, pmd, orig_entry);
1848 flush_pmd_tlb_range(vma, mmun_start, mmun_end);
1849 mmu_notifier_invalidate_range(mm, mmun_start, mmun_end);
1850 update_mmu_cache_pmd(vma, address, &entry);
1851 page_remove_rmap(new_page, true);
1852 goto fail_putback;
1853 }
1854
1855 mlock_migrate_page(new_page, page);
1856 page_remove_rmap(page, true);
1857 set_page_owner_migrate_reason(new_page, MR_NUMA_MISPLACED);
1858
1859 spin_unlock(ptl);
1860 mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
1861
1862
1863 get_page(new_page);
1864 putback_lru_page(new_page);
1865
1866 unlock_page(new_page);
1867 unlock_page(page);
1868 put_page(page);
1869 put_page(page);
1870
1871 count_vm_events(PGMIGRATE_SUCCESS, HPAGE_PMD_NR);
1872 count_vm_numa_events(NUMA_PAGE_MIGRATE, HPAGE_PMD_NR);
1873
1874 mod_zone_page_state(page_zone(page),
1875 NR_ISOLATED_ANON + page_lru,
1876 -HPAGE_PMD_NR);
1877 return isolated;
1878
1879out_fail:
1880 count_vm_events(PGMIGRATE_FAIL, HPAGE_PMD_NR);
1881out_dropref:
1882 ptl = pmd_lock(mm, pmd);
1883 if (pmd_same(*pmd, entry)) {
1884 entry = pmd_modify(entry, vma->vm_page_prot);
1885 set_pmd_at(mm, mmun_start, pmd, entry);
1886 update_mmu_cache_pmd(vma, address, &entry);
1887 }
1888 spin_unlock(ptl);
1889
1890out_unlock:
1891 unlock_page(page);
1892 put_page(page);
1893 return 0;
1894}
1895#endif
1896
1897#endif
1898