2 * Memory Migration functionality - linux/mm/migration.c
4 * Copyright (C) 2006 Silicon Graphics, Inc., Christoph Lameter
6 * Page migration was first developed in the context of the memory hotplug
7 * project. The main authors of the migration code are:
9 * IWAMOTO Toshihiro <iwamoto@valinux.co.jp>
10 * Hirokazu Takahashi <taka@valinux.co.jp>
11 * Dave Hansen <haveblue@us.ibm.com>
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 #include <linux/mmu_notifier.h>
40 #include <linux/page_idle.h>
42 #include <asm/tlbflush.h>
44 #define CREATE_TRACE_POINTS
45 #include <trace/events/migrate.h>
50 * migrate_prep() needs to be called before we start compiling a list of pages
51 * to be migrated using isolate_lru_page(). If scheduling work on other CPUs is
52 * undesirable, use migrate_prep_local()
54 int migrate_prep(void)
57 * Clear the LRU lists so pages can be isolated.
58 * Note that pages may be moved off the LRU after we have
59 * drained them. Those pages will fail to migrate like other
60 * pages that may be busy.
67 /* Do the necessary work of migrate_prep but not if it involves other CPUs */
68 int migrate_prep_local(void)
76 * Put previously isolated pages back onto the appropriate lists
77 * from where they were once taken off for compaction/migration.
79 * This function shall be used whenever the isolated pageset has been
80 * built from lru, balloon, hugetlbfs page. See isolate_migratepages_range()
81 * and isolate_huge_page().
83 void putback_movable_pages(struct list_head
*l
)
88 list_for_each_entry_safe(page
, page2
, l
, lru
) {
89 if (unlikely(PageHuge(page
))) {
90 putback_active_hugepage(page
);
94 dec_zone_page_state(page
, NR_ISOLATED_ANON
+
95 page_is_file_cache(page
));
96 if (unlikely(isolated_balloon_page(page
)))
97 balloon_page_putback(page
);
99 putback_lru_page(page
);
104 * Restore a potential migration pte to a working pte entry
106 static int remove_migration_pte(struct page
*new, struct vm_area_struct
*vma
,
107 unsigned long addr
, void *old
)
109 struct mm_struct
*mm
= vma
->vm_mm
;
115 if (unlikely(PageHuge(new))) {
116 ptep
= huge_pte_offset(mm
, addr
);
119 ptl
= huge_pte_lockptr(hstate_vma(vma
), mm
, ptep
);
121 pmd
= mm_find_pmd(mm
, addr
);
125 ptep
= pte_offset_map(pmd
, addr
);
128 * Peek to check is_swap_pte() before taking ptlock? No, we
129 * can race mremap's move_ptes(), which skips anon_vma lock.
132 ptl
= pte_lockptr(mm
, pmd
);
137 if (!is_swap_pte(pte
))
140 entry
= pte_to_swp_entry(pte
);
142 if (!is_migration_entry(entry
) ||
143 migration_entry_to_page(entry
) != old
)
147 pte
= pte_mkold(mk_pte(new, vma
->vm_page_prot
));
148 if (pte_swp_soft_dirty(*ptep
))
149 pte
= pte_mksoft_dirty(pte
);
151 /* Recheck VMA as permissions can change since migration started */
152 if (is_write_migration_entry(entry
))
153 pte
= maybe_mkwrite(pte
, vma
);
155 #ifdef CONFIG_HUGETLB_PAGE
157 pte
= pte_mkhuge(pte
);
158 pte
= arch_make_huge_pte(pte
, vma
, new, 0);
161 flush_dcache_page(new);
162 set_pte_at(mm
, addr
, ptep
, pte
);
166 hugepage_add_anon_rmap(new, vma
, addr
);
169 } else if (PageAnon(new))
170 page_add_anon_rmap(new, vma
, addr
);
172 page_add_file_rmap(new);
174 /* No need to invalidate - it was non-present before */
175 update_mmu_cache(vma
, addr
, ptep
);
177 pte_unmap_unlock(ptep
, ptl
);
183 * Get rid of all migration entries and replace them by
184 * references to the indicated page.
186 static void remove_migration_ptes(struct page
*old
, struct page
*new)
188 struct rmap_walk_control rwc
= {
189 .rmap_one
= remove_migration_pte
,
193 rmap_walk(new, &rwc
);
197 * Something used the pte of a page under migration. We need to
198 * get to the page and wait until migration is finished.
199 * When we return from this function the fault will be retried.
201 void __migration_entry_wait(struct mm_struct
*mm
, pte_t
*ptep
,
210 if (!is_swap_pte(pte
))
213 entry
= pte_to_swp_entry(pte
);
214 if (!is_migration_entry(entry
))
217 page
= migration_entry_to_page(entry
);
220 * Once radix-tree replacement of page migration started, page_count
221 * *must* be zero. And, we don't want to call wait_on_page_locked()
222 * against a page without get_page().
223 * So, we use get_page_unless_zero(), here. Even failed, page fault
226 if (!get_page_unless_zero(page
))
228 pte_unmap_unlock(ptep
, ptl
);
229 wait_on_page_locked(page
);
233 pte_unmap_unlock(ptep
, ptl
);
236 void migration_entry_wait(struct mm_struct
*mm
, pmd_t
*pmd
,
237 unsigned long address
)
239 spinlock_t
*ptl
= pte_lockptr(mm
, pmd
);
240 pte_t
*ptep
= pte_offset_map(pmd
, address
);
241 __migration_entry_wait(mm
, ptep
, ptl
);
244 void migration_entry_wait_huge(struct vm_area_struct
*vma
,
245 struct mm_struct
*mm
, pte_t
*pte
)
247 spinlock_t
*ptl
= huge_pte_lockptr(hstate_vma(vma
), mm
, pte
);
248 __migration_entry_wait(mm
, pte
, ptl
);
252 /* Returns true if all buffers are successfully locked */
253 static bool buffer_migrate_lock_buffers(struct buffer_head
*head
,
254 enum migrate_mode mode
)
256 struct buffer_head
*bh
= head
;
258 /* Simple case, sync compaction */
259 if (mode
!= MIGRATE_ASYNC
) {
263 bh
= bh
->b_this_page
;
265 } while (bh
!= head
);
270 /* async case, we cannot block on lock_buffer so use trylock_buffer */
273 if (!trylock_buffer(bh
)) {
275 * We failed to lock the buffer and cannot stall in
276 * async migration. Release the taken locks
278 struct buffer_head
*failed_bh
= bh
;
281 while (bh
!= failed_bh
) {
284 bh
= bh
->b_this_page
;
289 bh
= bh
->b_this_page
;
290 } while (bh
!= head
);
294 static inline bool buffer_migrate_lock_buffers(struct buffer_head
*head
,
295 enum migrate_mode mode
)
299 #endif /* CONFIG_BLOCK */
302 * Replace the page in the mapping.
304 * The number of remaining references must be:
305 * 1 for anonymous pages without a mapping
306 * 2 for pages with a mapping
307 * 3 for pages with a mapping and PagePrivate/PagePrivate2 set.
309 int migrate_page_move_mapping(struct address_space
*mapping
,
310 struct page
*newpage
, struct page
*page
,
311 struct buffer_head
*head
, enum migrate_mode mode
,
314 int expected_count
= 1 + extra_count
;
318 /* Anonymous page without mapping */
319 if (page_count(page
) != expected_count
)
321 return MIGRATEPAGE_SUCCESS
;
324 spin_lock_irq(&mapping
->tree_lock
);
326 pslot
= radix_tree_lookup_slot(&mapping
->page_tree
,
329 expected_count
+= 1 + page_has_private(page
);
330 if (page_count(page
) != expected_count
||
331 radix_tree_deref_slot_protected(pslot
, &mapping
->tree_lock
) != page
) {
332 spin_unlock_irq(&mapping
->tree_lock
);
336 if (!page_freeze_refs(page
, expected_count
)) {
337 spin_unlock_irq(&mapping
->tree_lock
);
342 * In the async migration case of moving a page with buffers, lock the
343 * buffers using trylock before the mapping is moved. If the mapping
344 * was moved, we later failed to lock the buffers and could not move
345 * the mapping back due to an elevated page count, we would have to
346 * block waiting on other references to be dropped.
348 if (mode
== MIGRATE_ASYNC
&& head
&&
349 !buffer_migrate_lock_buffers(head
, mode
)) {
350 page_unfreeze_refs(page
, expected_count
);
351 spin_unlock_irq(&mapping
->tree_lock
);
356 * Now we know that no one else is looking at the page.
358 get_page(newpage
); /* add cache reference */
359 if (PageSwapCache(page
)) {
360 SetPageSwapCache(newpage
);
361 set_page_private(newpage
, page_private(page
));
364 radix_tree_replace_slot(pslot
, newpage
);
367 * Drop cache reference from old page by unfreezing
368 * to one less reference.
369 * We know this isn't the last reference.
371 page_unfreeze_refs(page
, expected_count
- 1);
374 * If moved to a different zone then also account
375 * the page for that zone. Other VM counters will be
376 * taken care of when we establish references to the
377 * new page and drop references to the old page.
379 * Note that anonymous pages are accounted for
380 * via NR_FILE_PAGES and NR_ANON_PAGES if they
381 * are mapped to swap space.
383 __dec_zone_page_state(page
, NR_FILE_PAGES
);
384 __inc_zone_page_state(newpage
, NR_FILE_PAGES
);
385 if (!PageSwapCache(page
) && PageSwapBacked(page
)) {
386 __dec_zone_page_state(page
, NR_SHMEM
);
387 __inc_zone_page_state(newpage
, NR_SHMEM
);
389 spin_unlock_irq(&mapping
->tree_lock
);
391 return MIGRATEPAGE_SUCCESS
;
395 * The expected number of remaining references is the same as that
396 * of migrate_page_move_mapping().
398 int migrate_huge_page_move_mapping(struct address_space
*mapping
,
399 struct page
*newpage
, struct page
*page
)
405 if (page_count(page
) != 1)
407 return MIGRATEPAGE_SUCCESS
;
410 spin_lock_irq(&mapping
->tree_lock
);
412 pslot
= radix_tree_lookup_slot(&mapping
->page_tree
,
415 expected_count
= 2 + page_has_private(page
);
416 if (page_count(page
) != expected_count
||
417 radix_tree_deref_slot_protected(pslot
, &mapping
->tree_lock
) != page
) {
418 spin_unlock_irq(&mapping
->tree_lock
);
422 if (!page_freeze_refs(page
, expected_count
)) {
423 spin_unlock_irq(&mapping
->tree_lock
);
429 radix_tree_replace_slot(pslot
, newpage
);
431 page_unfreeze_refs(page
, expected_count
- 1);
433 spin_unlock_irq(&mapping
->tree_lock
);
434 return MIGRATEPAGE_SUCCESS
;
438 * Gigantic pages are so large that we do not guarantee that page++ pointer
439 * arithmetic will work across the entire page. We need something more
442 static void __copy_gigantic_page(struct page
*dst
, struct page
*src
,
446 struct page
*dst_base
= dst
;
447 struct page
*src_base
= src
;
449 for (i
= 0; i
< nr_pages
; ) {
451 copy_highpage(dst
, src
);
454 dst
= mem_map_next(dst
, dst_base
, i
);
455 src
= mem_map_next(src
, src_base
, i
);
459 static void copy_huge_page(struct page
*dst
, struct page
*src
)
466 struct hstate
*h
= page_hstate(src
);
467 nr_pages
= pages_per_huge_page(h
);
469 if (unlikely(nr_pages
> MAX_ORDER_NR_PAGES
)) {
470 __copy_gigantic_page(dst
, src
, nr_pages
);
475 BUG_ON(!PageTransHuge(src
));
476 nr_pages
= hpage_nr_pages(src
);
479 for (i
= 0; i
< nr_pages
; i
++) {
481 copy_highpage(dst
+ i
, src
+ i
);
486 * Copy the page to its new location
488 void migrate_page_copy(struct page
*newpage
, struct page
*page
)
492 if (PageHuge(page
) || PageTransHuge(page
))
493 copy_huge_page(newpage
, page
);
495 copy_highpage(newpage
, page
);
498 SetPageError(newpage
);
499 if (PageReferenced(page
))
500 SetPageReferenced(newpage
);
501 if (PageUptodate(page
))
502 SetPageUptodate(newpage
);
503 if (TestClearPageActive(page
)) {
504 VM_BUG_ON_PAGE(PageUnevictable(page
), page
);
505 SetPageActive(newpage
);
506 } else if (TestClearPageUnevictable(page
))
507 SetPageUnevictable(newpage
);
508 if (PageChecked(page
))
509 SetPageChecked(newpage
);
510 if (PageMappedToDisk(page
))
511 SetPageMappedToDisk(newpage
);
513 if (PageDirty(page
)) {
514 clear_page_dirty_for_io(page
);
516 * Want to mark the page and the radix tree as dirty, and
517 * redo the accounting that clear_page_dirty_for_io undid,
518 * but we can't use set_page_dirty because that function
519 * is actually a signal that all of the page has become dirty.
520 * Whereas only part of our page may be dirty.
522 if (PageSwapBacked(page
))
523 SetPageDirty(newpage
);
525 __set_page_dirty_nobuffers(newpage
);
528 if (page_is_young(page
))
529 set_page_young(newpage
);
530 if (page_is_idle(page
))
531 set_page_idle(newpage
);
534 * Copy NUMA information to the new page, to prevent over-eager
535 * future migrations of this same page.
537 cpupid
= page_cpupid_xchg_last(page
, -1);
538 page_cpupid_xchg_last(newpage
, cpupid
);
540 mlock_migrate_page(newpage
, page
);
541 ksm_migrate_page(newpage
, page
);
543 * Please do not reorder this without considering how mm/ksm.c's
544 * get_ksm_page() depends upon ksm_migrate_page() and PageSwapCache().
546 if (PageSwapCache(page
))
547 ClearPageSwapCache(page
);
548 ClearPagePrivate(page
);
549 set_page_private(page
, 0);
552 * If any waiters have accumulated on the new page then
555 if (PageWriteback(newpage
))
556 end_page_writeback(newpage
);
559 /************************************************************
560 * Migration functions
561 ***********************************************************/
564 * Common logic to directly migrate a single page suitable for
565 * pages that do not use PagePrivate/PagePrivate2.
567 * Pages are locked upon entry and exit.
569 int migrate_page(struct address_space
*mapping
,
570 struct page
*newpage
, struct page
*page
,
571 enum migrate_mode mode
)
575 BUG_ON(PageWriteback(page
)); /* Writeback must be complete */
577 rc
= migrate_page_move_mapping(mapping
, newpage
, page
, NULL
, mode
, 0);
579 if (rc
!= MIGRATEPAGE_SUCCESS
)
582 migrate_page_copy(newpage
, page
);
583 return MIGRATEPAGE_SUCCESS
;
585 EXPORT_SYMBOL(migrate_page
);
589 * Migration function for pages with buffers. This function can only be used
590 * if the underlying filesystem guarantees that no other references to "page"
593 int buffer_migrate_page(struct address_space
*mapping
,
594 struct page
*newpage
, struct page
*page
, enum migrate_mode mode
)
596 struct buffer_head
*bh
, *head
;
599 if (!page_has_buffers(page
))
600 return migrate_page(mapping
, newpage
, page
, mode
);
602 head
= page_buffers(page
);
604 rc
= migrate_page_move_mapping(mapping
, newpage
, page
, head
, mode
, 0);
606 if (rc
!= MIGRATEPAGE_SUCCESS
)
610 * In the async case, migrate_page_move_mapping locked the buffers
611 * with an IRQ-safe spinlock held. In the sync case, the buffers
612 * need to be locked now
614 if (mode
!= MIGRATE_ASYNC
)
615 BUG_ON(!buffer_migrate_lock_buffers(head
, mode
));
617 ClearPagePrivate(page
);
618 set_page_private(newpage
, page_private(page
));
619 set_page_private(page
, 0);
625 set_bh_page(bh
, newpage
, bh_offset(bh
));
626 bh
= bh
->b_this_page
;
628 } while (bh
!= head
);
630 SetPagePrivate(newpage
);
632 migrate_page_copy(newpage
, page
);
638 bh
= bh
->b_this_page
;
640 } while (bh
!= head
);
642 return MIGRATEPAGE_SUCCESS
;
644 EXPORT_SYMBOL(buffer_migrate_page
);
648 * Writeback a page to clean the dirty state
650 static int writeout(struct address_space
*mapping
, struct page
*page
)
652 struct writeback_control wbc
= {
653 .sync_mode
= WB_SYNC_NONE
,
656 .range_end
= LLONG_MAX
,
661 if (!mapping
->a_ops
->writepage
)
662 /* No write method for the address space */
665 if (!clear_page_dirty_for_io(page
))
666 /* Someone else already triggered a write */
670 * A dirty page may imply that the underlying filesystem has
671 * the page on some queue. So the page must be clean for
672 * migration. Writeout may mean we loose the lock and the
673 * page state is no longer what we checked for earlier.
674 * At this point we know that the migration attempt cannot
677 remove_migration_ptes(page
, page
);
679 rc
= mapping
->a_ops
->writepage(page
, &wbc
);
681 if (rc
!= AOP_WRITEPAGE_ACTIVATE
)
682 /* unlocked. Relock */
685 return (rc
< 0) ? -EIO
: -EAGAIN
;
689 * Default handling if a filesystem does not provide a migration function.
691 static int fallback_migrate_page(struct address_space
*mapping
,
692 struct page
*newpage
, struct page
*page
, enum migrate_mode mode
)
694 if (PageDirty(page
)) {
695 /* Only writeback pages in full synchronous migration */
696 if (mode
!= MIGRATE_SYNC
)
698 return writeout(mapping
, page
);
702 * Buffers may be managed in a filesystem specific way.
703 * We must have no buffers or drop them.
705 if (page_has_private(page
) &&
706 !try_to_release_page(page
, GFP_KERNEL
))
709 return migrate_page(mapping
, newpage
, page
, mode
);
713 * Move a page to a newly allocated page
714 * The page is locked and all ptes have been successfully removed.
716 * The new page will have replaced the old page if this function
721 * MIGRATEPAGE_SUCCESS - success
723 static int move_to_new_page(struct page
*newpage
, struct page
*page
,
724 int page_was_mapped
, enum migrate_mode mode
)
726 struct address_space
*mapping
;
730 * Block others from accessing the page when we get around to
731 * establishing additional references. We are the only one
732 * holding a reference to the new page at this point.
734 if (!trylock_page(newpage
))
737 /* Prepare mapping for the new page.*/
738 newpage
->index
= page
->index
;
739 newpage
->mapping
= page
->mapping
;
740 if (PageSwapBacked(page
))
741 SetPageSwapBacked(newpage
);
744 * Indirectly called below, migrate_page_copy() copies PG_dirty and thus
745 * needs newpage's memcg set to transfer memcg dirty page accounting.
746 * So perform memcg migration in two steps:
747 * 1. set newpage->mem_cgroup (here)
748 * 2. clear page->mem_cgroup (below)
750 set_page_memcg(newpage
, page_memcg(page
));
752 mapping
= page_mapping(page
);
754 rc
= migrate_page(mapping
, newpage
, page
, mode
);
755 else if (mapping
->a_ops
->migratepage
)
757 * Most pages have a mapping and most filesystems provide a
758 * migratepage callback. Anonymous pages are part of swap
759 * space which also has its own migratepage callback. This
760 * is the most common path for page migration.
762 rc
= mapping
->a_ops
->migratepage(mapping
,
763 newpage
, page
, mode
);
765 rc
= fallback_migrate_page(mapping
, newpage
, page
, mode
);
767 if (rc
!= MIGRATEPAGE_SUCCESS
) {
768 set_page_memcg(newpage
, NULL
);
769 newpage
->mapping
= NULL
;
771 set_page_memcg(page
, NULL
);
773 remove_migration_ptes(page
, newpage
);
774 page
->mapping
= NULL
;
777 unlock_page(newpage
);
782 static int __unmap_and_move(struct page
*page
, struct page
*newpage
,
783 int force
, enum migrate_mode mode
)
786 int page_was_mapped
= 0;
787 struct anon_vma
*anon_vma
= NULL
;
789 if (!trylock_page(page
)) {
790 if (!force
|| mode
== MIGRATE_ASYNC
)
794 * It's not safe for direct compaction to call lock_page.
795 * For example, during page readahead pages are added locked
796 * to the LRU. Later, when the IO completes the pages are
797 * marked uptodate and unlocked. However, the queueing
798 * could be merging multiple pages for one bio (e.g.
799 * mpage_readpages). If an allocation happens for the
800 * second or third page, the process can end up locking
801 * the same page twice and deadlocking. Rather than
802 * trying to be clever about what pages can be locked,
803 * avoid the use of lock_page for direct compaction
806 if (current
->flags
& PF_MEMALLOC
)
812 if (PageWriteback(page
)) {
814 * Only in the case of a full synchronous migration is it
815 * necessary to wait for PageWriteback. In the async case,
816 * the retry loop is too short and in the sync-light case,
817 * the overhead of stalling is too much
819 if (mode
!= MIGRATE_SYNC
) {
825 wait_on_page_writeback(page
);
828 * By try_to_unmap(), page->mapcount goes down to 0 here. In this case,
829 * we cannot notice that anon_vma is freed while we migrates a page.
830 * This get_anon_vma() delays freeing anon_vma pointer until the end
831 * of migration. File cache pages are no problem because of page_lock()
832 * File Caches may use write_page() or lock_page() in migration, then,
833 * just care Anon page here.
835 if (PageAnon(page
) && !PageKsm(page
)) {
837 * Only page_lock_anon_vma_read() understands the subtleties of
838 * getting a hold on an anon_vma from outside one of its mms.
840 anon_vma
= page_get_anon_vma(page
);
845 } else if (PageSwapCache(page
)) {
847 * We cannot be sure that the anon_vma of an unmapped
848 * swapcache page is safe to use because we don't
849 * know in advance if the VMA that this page belonged
850 * to still exists. If the VMA and others sharing the
851 * data have been freed, then the anon_vma could
852 * already be invalid.
854 * To avoid this possibility, swapcache pages get
855 * migrated but are not remapped when migration
863 if (unlikely(isolated_balloon_page(page
))) {
865 * A ballooned page does not need any special attention from
866 * physical to virtual reverse mapping procedures.
867 * Skip any attempt to unmap PTEs or to remap swap cache,
868 * in order to avoid burning cycles at rmap level, and perform
869 * the page migration right away (proteced by page lock).
871 rc
= balloon_page_migrate(newpage
, page
, mode
);
876 * Corner case handling:
877 * 1. When a new swap-cache page is read into, it is added to the LRU
878 * and treated as swapcache but it has no rmap yet.
879 * Calling try_to_unmap() against a page->mapping==NULL page will
880 * trigger a BUG. So handle it here.
881 * 2. An orphaned page (see truncate_complete_page) might have
882 * fs-private metadata. The page can be picked up due to memory
883 * offlining. Everywhere else except page reclaim, the page is
884 * invisible to the vm, so the page can not be migrated. So try to
885 * free the metadata, so the page can be freed.
887 if (!page
->mapping
) {
888 VM_BUG_ON_PAGE(PageAnon(page
), page
);
889 if (page_has_private(page
)) {
890 try_to_free_buffers(page
);
896 /* Establish migration ptes or remove ptes */
897 if (page_mapped(page
)) {
899 TTU_MIGRATION
|TTU_IGNORE_MLOCK
|TTU_IGNORE_ACCESS
);
904 if (!page_mapped(page
))
905 rc
= move_to_new_page(newpage
, page
, page_was_mapped
, mode
);
907 if (rc
&& page_was_mapped
)
908 remove_migration_ptes(page
, page
);
910 /* Drop an anon_vma reference if we took one */
912 put_anon_vma(anon_vma
);
921 * gcc 4.7 and 4.8 on arm get an ICEs when inlining unmap_and_move(). Work
924 #if (GCC_VERSION >= 40700 && GCC_VERSION < 40900) && defined(CONFIG_ARM)
925 #define ICE_noinline noinline
931 * Obtain the lock on page, remove all ptes and migrate the page
932 * to the newly allocated page in newpage.
934 static ICE_noinline
int unmap_and_move(new_page_t get_new_page
,
935 free_page_t put_new_page
,
936 unsigned long private, struct page
*page
,
937 int force
, enum migrate_mode mode
,
938 enum migrate_reason reason
)
942 struct page
*newpage
= get_new_page(page
, private, &result
);
947 if (page_count(page
) == 1) {
948 /* page was freed from under us. So we are done. */
952 if (unlikely(PageTransHuge(page
)))
953 if (unlikely(split_huge_page(page
)))
956 rc
= __unmap_and_move(page
, newpage
, force
, mode
);
961 * A page that has been migrated has all references
962 * removed and will be freed. A page that has not been
963 * migrated will have kepts its references and be
966 list_del(&page
->lru
);
967 dec_zone_page_state(page
, NR_ISOLATED_ANON
+
968 page_is_file_cache(page
));
969 /* Soft-offlined page shouldn't go through lru cache list */
970 if (reason
== MR_MEMORY_FAILURE
) {
972 if (!test_set_page_hwpoison(page
))
973 num_poisoned_pages_inc();
975 putback_lru_page(page
);
979 * If migration was not successful and there's a freeing callback, use
980 * it. Otherwise, putback_lru_page() will drop the reference grabbed
983 if (rc
!= MIGRATEPAGE_SUCCESS
&& put_new_page
) {
984 ClearPageSwapBacked(newpage
);
985 put_new_page(newpage
, private);
986 } else if (unlikely(__is_movable_balloon_page(newpage
))) {
987 /* drop our reference, page already in the balloon */
990 putback_lru_page(newpage
);
996 *result
= page_to_nid(newpage
);
1002 * Counterpart of unmap_and_move_page() for hugepage migration.
1004 * This function doesn't wait the completion of hugepage I/O
1005 * because there is no race between I/O and migration for hugepage.
1006 * Note that currently hugepage I/O occurs only in direct I/O
1007 * where no lock is held and PG_writeback is irrelevant,
1008 * and writeback status of all subpages are counted in the reference
1009 * count of the head page (i.e. if all subpages of a 2MB hugepage are
1010 * under direct I/O, the reference of the head page is 512 and a bit more.)
1011 * This means that when we try to migrate hugepage whose subpages are
1012 * doing direct I/O, some references remain after try_to_unmap() and
1013 * hugepage migration fails without data corruption.
1015 * There is also no race when direct I/O is issued on the page under migration,
1016 * because then pte is replaced with migration swap entry and direct I/O code
1017 * will wait in the page fault for migration to complete.
1019 static int unmap_and_move_huge_page(new_page_t get_new_page
,
1020 free_page_t put_new_page
, unsigned long private,
1021 struct page
*hpage
, int force
,
1022 enum migrate_mode mode
)
1026 int page_was_mapped
= 0;
1027 struct page
*new_hpage
;
1028 struct anon_vma
*anon_vma
= NULL
;
1031 * Movability of hugepages depends on architectures and hugepage size.
1032 * This check is necessary because some callers of hugepage migration
1033 * like soft offline and memory hotremove don't walk through page
1034 * tables or check whether the hugepage is pmd-based or not before
1035 * kicking migration.
1037 if (!hugepage_migration_supported(page_hstate(hpage
))) {
1038 putback_active_hugepage(hpage
);
1042 new_hpage
= get_new_page(hpage
, private, &result
);
1048 if (!trylock_page(hpage
)) {
1049 if (!force
|| mode
!= MIGRATE_SYNC
)
1054 if (PageAnon(hpage
))
1055 anon_vma
= page_get_anon_vma(hpage
);
1057 if (page_mapped(hpage
)) {
1059 TTU_MIGRATION
|TTU_IGNORE_MLOCK
|TTU_IGNORE_ACCESS
);
1060 page_was_mapped
= 1;
1063 if (!page_mapped(hpage
))
1064 rc
= move_to_new_page(new_hpage
, hpage
, page_was_mapped
, mode
);
1066 if (rc
!= MIGRATEPAGE_SUCCESS
&& page_was_mapped
)
1067 remove_migration_ptes(hpage
, hpage
);
1070 put_anon_vma(anon_vma
);
1072 if (rc
== MIGRATEPAGE_SUCCESS
)
1073 hugetlb_cgroup_migrate(hpage
, new_hpage
);
1078 putback_active_hugepage(hpage
);
1081 * If migration was not successful and there's a freeing callback, use
1082 * it. Otherwise, put_page() will drop the reference grabbed during
1085 if (rc
!= MIGRATEPAGE_SUCCESS
&& put_new_page
)
1086 put_new_page(new_hpage
, private);
1088 putback_active_hugepage(new_hpage
);
1094 *result
= page_to_nid(new_hpage
);
1100 * migrate_pages - migrate the pages specified in a list, to the free pages
1101 * supplied as the target for the page migration
1103 * @from: The list of pages to be migrated.
1104 * @get_new_page: The function used to allocate free pages to be used
1105 * as the target of the page migration.
1106 * @put_new_page: The function used to free target pages if migration
1107 * fails, or NULL if no special handling is necessary.
1108 * @private: Private data to be passed on to get_new_page()
1109 * @mode: The migration mode that specifies the constraints for
1110 * page migration, if any.
1111 * @reason: The reason for page migration.
1113 * The function returns after 10 attempts or if no pages are movable any more
1114 * because the list has become empty or no retryable pages exist any more.
1115 * The caller should call putback_lru_pages() to return pages to the LRU
1116 * or free list only if ret != 0.
1118 * Returns the number of pages that were not migrated, or an error code.
1120 int migrate_pages(struct list_head
*from
, new_page_t get_new_page
,
1121 free_page_t put_new_page
, unsigned long private,
1122 enum migrate_mode mode
, int reason
)
1126 int nr_succeeded
= 0;
1130 int swapwrite
= current
->flags
& PF_SWAPWRITE
;
1134 current
->flags
|= PF_SWAPWRITE
;
1136 for(pass
= 0; pass
< 10 && retry
; pass
++) {
1139 list_for_each_entry_safe(page
, page2
, from
, lru
) {
1143 rc
= unmap_and_move_huge_page(get_new_page
,
1144 put_new_page
, private, page
,
1147 rc
= unmap_and_move(get_new_page
, put_new_page
,
1148 private, page
, pass
> 2, mode
,
1157 case MIGRATEPAGE_SUCCESS
:
1162 * Permanent failure (-EBUSY, -ENOSYS, etc.):
1163 * unlike -EAGAIN case, the failed page is
1164 * removed from migration page list and not
1165 * retried in the next outer loop.
1172 rc
= nr_failed
+ retry
;
1175 count_vm_events(PGMIGRATE_SUCCESS
, nr_succeeded
);
1177 count_vm_events(PGMIGRATE_FAIL
, nr_failed
);
1178 trace_mm_migrate_pages(nr_succeeded
, nr_failed
, mode
, reason
);
1181 current
->flags
&= ~PF_SWAPWRITE
;
1188 * Move a list of individual pages
1190 struct page_to_node
{
1197 static struct page
*new_page_node(struct page
*p
, unsigned long private,
1200 struct page_to_node
*pm
= (struct page_to_node
*)private;
1202 while (pm
->node
!= MAX_NUMNODES
&& pm
->page
!= p
)
1205 if (pm
->node
== MAX_NUMNODES
)
1208 *result
= &pm
->status
;
1211 return alloc_huge_page_node(page_hstate(compound_head(p
)),
1214 return __alloc_pages_node(pm
->node
,
1215 GFP_HIGHUSER_MOVABLE
| __GFP_THISNODE
, 0);
1219 * Move a set of pages as indicated in the pm array. The addr
1220 * field must be set to the virtual address of the page to be moved
1221 * and the node number must contain a valid target node.
1222 * The pm array ends with node = MAX_NUMNODES.
1224 static int do_move_page_to_node_array(struct mm_struct
*mm
,
1225 struct page_to_node
*pm
,
1229 struct page_to_node
*pp
;
1230 LIST_HEAD(pagelist
);
1232 down_read(&mm
->mmap_sem
);
1235 * Build a list of pages to migrate
1237 for (pp
= pm
; pp
->node
!= MAX_NUMNODES
; pp
++) {
1238 struct vm_area_struct
*vma
;
1242 vma
= find_vma(mm
, pp
->addr
);
1243 if (!vma
|| pp
->addr
< vma
->vm_start
|| !vma_migratable(vma
))
1246 /* FOLL_DUMP to ignore special (like zero) pages */
1247 page
= follow_page(vma
, pp
->addr
,
1248 FOLL_GET
| FOLL_SPLIT
| FOLL_DUMP
);
1250 err
= PTR_ERR(page
);
1259 err
= page_to_nid(page
);
1261 if (err
== pp
->node
)
1263 * Node already in the right place
1268 if (page_mapcount(page
) > 1 &&
1272 if (PageHuge(page
)) {
1274 isolate_huge_page(page
, &pagelist
);
1278 err
= isolate_lru_page(page
);
1280 list_add_tail(&page
->lru
, &pagelist
);
1281 inc_zone_page_state(page
, NR_ISOLATED_ANON
+
1282 page_is_file_cache(page
));
1286 * Either remove the duplicate refcount from
1287 * isolate_lru_page() or drop the page ref if it was
1296 if (!list_empty(&pagelist
)) {
1297 err
= migrate_pages(&pagelist
, new_page_node
, NULL
,
1298 (unsigned long)pm
, MIGRATE_SYNC
, MR_SYSCALL
);
1300 putback_movable_pages(&pagelist
);
1303 up_read(&mm
->mmap_sem
);
1308 * Migrate an array of page address onto an array of nodes and fill
1309 * the corresponding array of status.
1311 static int do_pages_move(struct mm_struct
*mm
, nodemask_t task_nodes
,
1312 unsigned long nr_pages
,
1313 const void __user
* __user
*pages
,
1314 const int __user
*nodes
,
1315 int __user
*status
, int flags
)
1317 struct page_to_node
*pm
;
1318 unsigned long chunk_nr_pages
;
1319 unsigned long chunk_start
;
1323 pm
= (struct page_to_node
*)__get_free_page(GFP_KERNEL
);
1330 * Store a chunk of page_to_node array in a page,
1331 * but keep the last one as a marker
1333 chunk_nr_pages
= (PAGE_SIZE
/ sizeof(struct page_to_node
)) - 1;
1335 for (chunk_start
= 0;
1336 chunk_start
< nr_pages
;
1337 chunk_start
+= chunk_nr_pages
) {
1340 if (chunk_start
+ chunk_nr_pages
> nr_pages
)
1341 chunk_nr_pages
= nr_pages
- chunk_start
;
1343 /* fill the chunk pm with addrs and nodes from user-space */
1344 for (j
= 0; j
< chunk_nr_pages
; j
++) {
1345 const void __user
*p
;
1349 if (get_user(p
, pages
+ j
+ chunk_start
))
1351 pm
[j
].addr
= (unsigned long) p
;
1353 if (get_user(node
, nodes
+ j
+ chunk_start
))
1357 if (node
< 0 || node
>= MAX_NUMNODES
)
1360 if (!node_state(node
, N_MEMORY
))
1364 if (!node_isset(node
, task_nodes
))
1370 /* End marker for this chunk */
1371 pm
[chunk_nr_pages
].node
= MAX_NUMNODES
;
1373 /* Migrate this chunk */
1374 err
= do_move_page_to_node_array(mm
, pm
,
1375 flags
& MPOL_MF_MOVE_ALL
);
1379 /* Return status information */
1380 for (j
= 0; j
< chunk_nr_pages
; j
++)
1381 if (put_user(pm
[j
].status
, status
+ j
+ chunk_start
)) {
1389 free_page((unsigned long)pm
);
1395 * Determine the nodes of an array of pages and store it in an array of status.
1397 static void do_pages_stat_array(struct mm_struct
*mm
, unsigned long nr_pages
,
1398 const void __user
**pages
, int *status
)
1402 down_read(&mm
->mmap_sem
);
1404 for (i
= 0; i
< nr_pages
; i
++) {
1405 unsigned long addr
= (unsigned long)(*pages
);
1406 struct vm_area_struct
*vma
;
1410 vma
= find_vma(mm
, addr
);
1411 if (!vma
|| addr
< vma
->vm_start
)
1414 /* FOLL_DUMP to ignore special (like zero) pages */
1415 page
= follow_page(vma
, addr
, FOLL_DUMP
);
1417 err
= PTR_ERR(page
);
1421 err
= page
? page_to_nid(page
) : -ENOENT
;
1429 up_read(&mm
->mmap_sem
);
1433 * Determine the nodes of a user array of pages and store it in
1434 * a user array of status.
1436 static int do_pages_stat(struct mm_struct
*mm
, unsigned long nr_pages
,
1437 const void __user
* __user
*pages
,
1440 #define DO_PAGES_STAT_CHUNK_NR 16
1441 const void __user
*chunk_pages
[DO_PAGES_STAT_CHUNK_NR
];
1442 int chunk_status
[DO_PAGES_STAT_CHUNK_NR
];
1445 unsigned long chunk_nr
;
1447 chunk_nr
= nr_pages
;
1448 if (chunk_nr
> DO_PAGES_STAT_CHUNK_NR
)
1449 chunk_nr
= DO_PAGES_STAT_CHUNK_NR
;
1451 if (copy_from_user(chunk_pages
, pages
, chunk_nr
* sizeof(*chunk_pages
)))
1454 do_pages_stat_array(mm
, chunk_nr
, chunk_pages
, chunk_status
);
1456 if (copy_to_user(status
, chunk_status
, chunk_nr
* sizeof(*status
)))
1461 nr_pages
-= chunk_nr
;
1463 return nr_pages
? -EFAULT
: 0;
1467 * Move a list of pages in the address space of the currently executing
1470 SYSCALL_DEFINE6(move_pages
, pid_t
, pid
, unsigned long, nr_pages
,
1471 const void __user
* __user
*, pages
,
1472 const int __user
*, nodes
,
1473 int __user
*, status
, int, flags
)
1475 const struct cred
*cred
= current_cred(), *tcred
;
1476 struct task_struct
*task
;
1477 struct mm_struct
*mm
;
1479 nodemask_t task_nodes
;
1482 if (flags
& ~(MPOL_MF_MOVE
|MPOL_MF_MOVE_ALL
))
1485 if ((flags
& MPOL_MF_MOVE_ALL
) && !capable(CAP_SYS_NICE
))
1488 /* Find the mm_struct */
1490 task
= pid
? find_task_by_vpid(pid
) : current
;
1495 get_task_struct(task
);
1498 * Check if this process has the right to modify the specified
1499 * process. The right exists if the process has administrative
1500 * capabilities, superuser privileges or the same
1501 * userid as the target process.
1503 tcred
= __task_cred(task
);
1504 if (!uid_eq(cred
->euid
, tcred
->suid
) && !uid_eq(cred
->euid
, tcred
->uid
) &&
1505 !uid_eq(cred
->uid
, tcred
->suid
) && !uid_eq(cred
->uid
, tcred
->uid
) &&
1506 !capable(CAP_SYS_NICE
)) {
1513 err
= security_task_movememory(task
);
1517 task_nodes
= cpuset_mems_allowed(task
);
1518 mm
= get_task_mm(task
);
1519 put_task_struct(task
);
1525 err
= do_pages_move(mm
, task_nodes
, nr_pages
, pages
,
1526 nodes
, status
, flags
);
1528 err
= do_pages_stat(mm
, nr_pages
, pages
, status
);
1534 put_task_struct(task
);
1538 #ifdef CONFIG_NUMA_BALANCING
1540 * Returns true if this is a safe migration target node for misplaced NUMA
1541 * pages. Currently it only checks the watermarks which crude
1543 static bool migrate_balanced_pgdat(struct pglist_data
*pgdat
,
1544 unsigned long nr_migrate_pages
)
1547 for (z
= pgdat
->nr_zones
- 1; z
>= 0; z
--) {
1548 struct zone
*zone
= pgdat
->node_zones
+ z
;
1550 if (!populated_zone(zone
))
1553 if (!zone_reclaimable(zone
))
1556 /* Avoid waking kswapd by allocating pages_to_migrate pages. */
1557 if (!zone_watermark_ok(zone
, 0,
1558 high_wmark_pages(zone
) +
1567 static struct page
*alloc_misplaced_dst_page(struct page
*page
,
1571 int nid
= (int) data
;
1572 struct page
*newpage
;
1574 newpage
= __alloc_pages_node(nid
,
1575 (GFP_HIGHUSER_MOVABLE
|
1576 __GFP_THISNODE
| __GFP_NOMEMALLOC
|
1577 __GFP_NORETRY
| __GFP_NOWARN
) &
1584 * page migration rate limiting control.
1585 * Do not migrate more than @pages_to_migrate in a @migrate_interval_millisecs
1586 * window of time. Default here says do not migrate more than 1280M per second.
1588 static unsigned int migrate_interval_millisecs __read_mostly
= 100;
1589 static unsigned int ratelimit_pages __read_mostly
= 128 << (20 - PAGE_SHIFT
);
1591 /* Returns true if the node is migrate rate-limited after the update */
1592 static bool numamigrate_update_ratelimit(pg_data_t
*pgdat
,
1593 unsigned long nr_pages
)
1596 * Rate-limit the amount of data that is being migrated to a node.
1597 * Optimal placement is no good if the memory bus is saturated and
1598 * all the time is being spent migrating!
1600 if (time_after(jiffies
, pgdat
->numabalancing_migrate_next_window
)) {
1601 spin_lock(&pgdat
->numabalancing_migrate_lock
);
1602 pgdat
->numabalancing_migrate_nr_pages
= 0;
1603 pgdat
->numabalancing_migrate_next_window
= jiffies
+
1604 msecs_to_jiffies(migrate_interval_millisecs
);
1605 spin_unlock(&pgdat
->numabalancing_migrate_lock
);
1607 if (pgdat
->numabalancing_migrate_nr_pages
> ratelimit_pages
) {
1608 trace_mm_numa_migrate_ratelimit(current
, pgdat
->node_id
,
1614 * This is an unlocked non-atomic update so errors are possible.
1615 * The consequences are failing to migrate when we potentiall should
1616 * have which is not severe enough to warrant locking. If it is ever
1617 * a problem, it can be converted to a per-cpu counter.
1619 pgdat
->numabalancing_migrate_nr_pages
+= nr_pages
;
1623 static int numamigrate_isolate_page(pg_data_t
*pgdat
, struct page
*page
)
1627 VM_BUG_ON_PAGE(compound_order(page
) && !PageTransHuge(page
), page
);
1629 /* Avoid migrating to a node that is nearly full */
1630 if (!migrate_balanced_pgdat(pgdat
, 1UL << compound_order(page
)))
1633 if (isolate_lru_page(page
))
1637 * migrate_misplaced_transhuge_page() skips page migration's usual
1638 * check on page_count(), so we must do it here, now that the page
1639 * has been isolated: a GUP pin, or any other pin, prevents migration.
1640 * The expected page count is 3: 1 for page's mapcount and 1 for the
1641 * caller's pin and 1 for the reference taken by isolate_lru_page().
1643 if (PageTransHuge(page
) && page_count(page
) != 3) {
1644 putback_lru_page(page
);
1648 page_lru
= page_is_file_cache(page
);
1649 mod_zone_page_state(page_zone(page
), NR_ISOLATED_ANON
+ page_lru
,
1650 hpage_nr_pages(page
));
1653 * Isolating the page has taken another reference, so the
1654 * caller's reference can be safely dropped without the page
1655 * disappearing underneath us during migration.
1661 bool pmd_trans_migrating(pmd_t pmd
)
1663 struct page
*page
= pmd_page(pmd
);
1664 return PageLocked(page
);
1668 * Attempt to migrate a misplaced page to the specified destination
1669 * node. Caller is expected to have an elevated reference count on
1670 * the page that will be dropped by this function before returning.
1672 int migrate_misplaced_page(struct page
*page
, struct vm_area_struct
*vma
,
1675 pg_data_t
*pgdat
= NODE_DATA(node
);
1678 LIST_HEAD(migratepages
);
1681 * Don't migrate file pages that are mapped in multiple processes
1682 * with execute permissions as they are probably shared libraries.
1684 if (page_mapcount(page
) != 1 && page_is_file_cache(page
) &&
1685 (vma
->vm_flags
& VM_EXEC
))
1689 * Rate-limit the amount of data that is being migrated to a node.
1690 * Optimal placement is no good if the memory bus is saturated and
1691 * all the time is being spent migrating!
1693 if (numamigrate_update_ratelimit(pgdat
, 1))
1696 isolated
= numamigrate_isolate_page(pgdat
, page
);
1700 list_add(&page
->lru
, &migratepages
);
1701 nr_remaining
= migrate_pages(&migratepages
, alloc_misplaced_dst_page
,
1702 NULL
, node
, MIGRATE_ASYNC
,
1705 if (!list_empty(&migratepages
)) {
1706 list_del(&page
->lru
);
1707 dec_zone_page_state(page
, NR_ISOLATED_ANON
+
1708 page_is_file_cache(page
));
1709 putback_lru_page(page
);
1713 count_vm_numa_event(NUMA_PAGE_MIGRATE
);
1714 BUG_ON(!list_empty(&migratepages
));
1721 #endif /* CONFIG_NUMA_BALANCING */
1723 #if defined(CONFIG_NUMA_BALANCING) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
1725 * Migrates a THP to a given target node. page must be locked and is unlocked
1728 int migrate_misplaced_transhuge_page(struct mm_struct
*mm
,
1729 struct vm_area_struct
*vma
,
1730 pmd_t
*pmd
, pmd_t entry
,
1731 unsigned long address
,
1732 struct page
*page
, int node
)
1735 pg_data_t
*pgdat
= NODE_DATA(node
);
1737 struct page
*new_page
= NULL
;
1738 int page_lru
= page_is_file_cache(page
);
1739 unsigned long mmun_start
= address
& HPAGE_PMD_MASK
;
1740 unsigned long mmun_end
= mmun_start
+ HPAGE_PMD_SIZE
;
1744 * Rate-limit the amount of data that is being migrated to a node.
1745 * Optimal placement is no good if the memory bus is saturated and
1746 * all the time is being spent migrating!
1748 if (numamigrate_update_ratelimit(pgdat
, HPAGE_PMD_NR
))
1751 new_page
= alloc_pages_node(node
,
1752 (GFP_TRANSHUGE
| __GFP_THISNODE
) & ~__GFP_WAIT
,
1757 isolated
= numamigrate_isolate_page(pgdat
, page
);
1763 if (mm_tlb_flush_pending(mm
))
1764 flush_tlb_range(vma
, mmun_start
, mmun_end
);
1766 /* Prepare a page as a migration target */
1767 __set_page_locked(new_page
);
1768 SetPageSwapBacked(new_page
);
1770 /* anon mapping, we can simply copy page->mapping to the new page: */
1771 new_page
->mapping
= page
->mapping
;
1772 new_page
->index
= page
->index
;
1773 migrate_page_copy(new_page
, page
);
1774 WARN_ON(PageLRU(new_page
));
1776 /* Recheck the target PMD */
1777 mmu_notifier_invalidate_range_start(mm
, mmun_start
, mmun_end
);
1778 ptl
= pmd_lock(mm
, pmd
);
1779 if (unlikely(!pmd_same(*pmd
, entry
) || page_count(page
) != 2)) {
1782 mmu_notifier_invalidate_range_end(mm
, mmun_start
, mmun_end
);
1784 /* Reverse changes made by migrate_page_copy() */
1785 if (TestClearPageActive(new_page
))
1786 SetPageActive(page
);
1787 if (TestClearPageUnevictable(new_page
))
1788 SetPageUnevictable(page
);
1789 mlock_migrate_page(page
, new_page
);
1791 unlock_page(new_page
);
1792 put_page(new_page
); /* Free it */
1794 /* Retake the callers reference and putback on LRU */
1796 putback_lru_page(page
);
1797 mod_zone_page_state(page_zone(page
),
1798 NR_ISOLATED_ANON
+ page_lru
, -HPAGE_PMD_NR
);
1804 entry
= mk_pmd(new_page
, vma
->vm_page_prot
);
1805 entry
= pmd_mkhuge(entry
);
1806 entry
= maybe_pmd_mkwrite(pmd_mkdirty(entry
), vma
);
1809 * Clear the old entry under pagetable lock and establish the new PTE.
1810 * Any parallel GUP will either observe the old page blocking on the
1811 * page lock, block on the page table lock or observe the new page.
1812 * The SetPageUptodate on the new page and page_add_new_anon_rmap
1813 * guarantee the copy is visible before the pagetable update.
1815 flush_cache_range(vma
, mmun_start
, mmun_end
);
1816 page_add_anon_rmap(new_page
, vma
, mmun_start
);
1817 pmdp_huge_clear_flush_notify(vma
, mmun_start
, pmd
);
1818 set_pmd_at(mm
, mmun_start
, pmd
, entry
);
1819 flush_tlb_range(vma
, mmun_start
, mmun_end
);
1820 update_mmu_cache_pmd(vma
, address
, &entry
);
1822 if (page_count(page
) != 2) {
1823 set_pmd_at(mm
, mmun_start
, pmd
, orig_entry
);
1824 flush_tlb_range(vma
, mmun_start
, mmun_end
);
1825 mmu_notifier_invalidate_range(mm
, mmun_start
, mmun_end
);
1826 update_mmu_cache_pmd(vma
, address
, &entry
);
1827 page_remove_rmap(new_page
);
1831 mem_cgroup_migrate(page
, new_page
, false);
1833 page_remove_rmap(page
);
1836 mmu_notifier_invalidate_range_end(mm
, mmun_start
, mmun_end
);
1838 /* Take an "isolate" reference and put new page on the LRU. */
1840 putback_lru_page(new_page
);
1842 unlock_page(new_page
);
1844 put_page(page
); /* Drop the rmap reference */
1845 put_page(page
); /* Drop the LRU isolation reference */
1847 count_vm_events(PGMIGRATE_SUCCESS
, HPAGE_PMD_NR
);
1848 count_vm_numa_events(NUMA_PAGE_MIGRATE
, HPAGE_PMD_NR
);
1850 mod_zone_page_state(page_zone(page
),
1851 NR_ISOLATED_ANON
+ page_lru
,
1856 count_vm_events(PGMIGRATE_FAIL
, HPAGE_PMD_NR
);
1858 ptl
= pmd_lock(mm
, pmd
);
1859 if (pmd_same(*pmd
, entry
)) {
1860 entry
= pmd_modify(entry
, vma
->vm_page_prot
);
1861 set_pmd_at(mm
, mmun_start
, pmd
, entry
);
1862 update_mmu_cache_pmd(vma
, address
, &entry
);
1871 #endif /* CONFIG_NUMA_BALANCING */
1873 #endif /* CONFIG_NUMA */