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-rw-r--r--mm/migrate.c42
1 files changed, 14 insertions, 28 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index 246dcb973ae..a30ea5fcf9f 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -121,20 +121,6 @@ static void remove_migration_pte(struct vm_area_struct *vma,
121 if (!is_migration_entry(entry) || migration_entry_to_page(entry) != old) 121 if (!is_migration_entry(entry) || migration_entry_to_page(entry) != old)
122 goto out; 122 goto out;
123 123
124 /*
125 * Yes, ignore the return value from a GFP_ATOMIC mem_cgroup_charge.
126 * Failure is not an option here: we're now expected to remove every
127 * migration pte, and will cause crashes otherwise. Normally this
128 * is not an issue: mem_cgroup_prepare_migration bumped up the old
129 * page_cgroup count for safety, that's now attached to the new page,
130 * so this charge should just be another incrementation of the count,
131 * to keep in balance with rmap.c's mem_cgroup_uncharging. But if
132 * there's been a force_empty, those reference counts may no longer
133 * be reliable, and this charge can actually fail: oh well, we don't
134 * make the situation any worse by proceeding as if it had succeeded.
135 */
136 mem_cgroup_charge_migrate_fixup(new, mm, GFP_ATOMIC);
137
138 get_page(new); 124 get_page(new);
139 pte = pte_mkold(mk_pte(new, vma->vm_page_prot)); 125 pte = pte_mkold(mk_pte(new, vma->vm_page_prot));
140 if (is_write_migration_entry(entry)) 126 if (is_write_migration_entry(entry))
@@ -378,9 +364,6 @@ static void migrate_page_copy(struct page *newpage, struct page *page)
378 anon = PageAnon(page); 364 anon = PageAnon(page);
379 page->mapping = NULL; 365 page->mapping = NULL;
380 366
381 if (!anon) /* This page was removed from radix-tree. */
382 mem_cgroup_uncharge_cache_page(page);
383
384 /* 367 /*
385 * If any waiters have accumulated on the new page then 368 * If any waiters have accumulated on the new page then
386 * wake them up. 369 * wake them up.
@@ -614,6 +597,7 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
614 struct page *newpage = get_new_page(page, private, &result); 597 struct page *newpage = get_new_page(page, private, &result);
615 int rcu_locked = 0; 598 int rcu_locked = 0;
616 int charge = 0; 599 int charge = 0;
600 struct mem_cgroup *mem;
617 601
618 if (!newpage) 602 if (!newpage)
619 return -ENOMEM; 603 return -ENOMEM;
@@ -623,24 +607,26 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
623 goto move_newpage; 607 goto move_newpage;
624 } 608 }
625 609
626 charge = mem_cgroup_prepare_migration(page, newpage);
627 if (charge == -ENOMEM) {
628 rc = -ENOMEM;
629 goto move_newpage;
630 }
631 /* prepare cgroup just returns 0 or -ENOMEM */ 610 /* prepare cgroup just returns 0 or -ENOMEM */
632 BUG_ON(charge);
633
634 rc = -EAGAIN; 611 rc = -EAGAIN;
612
635 if (!trylock_page(page)) { 613 if (!trylock_page(page)) {
636 if (!force) 614 if (!force)
637 goto move_newpage; 615 goto move_newpage;
638 lock_page(page); 616 lock_page(page);
639 } 617 }
640 618
619 /* charge against new page */
620 charge = mem_cgroup_prepare_migration(page, &mem);
621 if (charge == -ENOMEM) {
622 rc = -ENOMEM;
623 goto unlock;
624 }
625 BUG_ON(charge);
626
641 if (PageWriteback(page)) { 627 if (PageWriteback(page)) {
642 if (!force) 628 if (!force)
643 goto unlock; 629 goto uncharge;
644 wait_on_page_writeback(page); 630 wait_on_page_writeback(page);
645 } 631 }
646 /* 632 /*
@@ -693,7 +679,9 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private,
693rcu_unlock: 679rcu_unlock:
694 if (rcu_locked) 680 if (rcu_locked)
695 rcu_read_unlock(); 681 rcu_read_unlock();
696 682uncharge:
683 if (!charge)
684 mem_cgroup_end_migration(mem, page, newpage);
697unlock: 685unlock:
698 unlock_page(page); 686 unlock_page(page);
699 687
@@ -709,8 +697,6 @@ unlock:
709 } 697 }
710 698
711move_newpage: 699move_newpage:
712 if (!charge)
713 mem_cgroup_end_migration(newpage);
714 700
715 /* 701 /*
716 * Move the new page to the LRU. If migration was not successful 702 * Move the new page to the LRU. If migration was not successful