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