diff options
Diffstat (limited to 'mm/migrate.c')
| -rw-r--r-- | mm/migrate.c | 42 |
1 files changed, 14 insertions, 28 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index 55373983c9c6..a30ea5fcf9f1 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -121,20 +121,6 @@ static void remove_migration_pte(struct vm_area_struct *vma, if (!is_migration_entry(entry) || migration_entry_to_page(entry) != old) goto out; - /* - * Yes, ignore the return value from a GFP_ATOMIC mem_cgroup_charge. - * Failure is not an option here: we're now expected to remove every - * migration pte, and will cause crashes otherwise. Normally this - * is not an issue: mem_cgroup_prepare_migration bumped up the old - * page_cgroup count for safety, that's now attached to the new page, - * so this charge should just be another incrementation of the count, - * to keep in balance with rmap.c's mem_cgroup_uncharging. But if - * there's been a force_empty, those reference counts may no longer - * be reliable, and this charge can actually fail: oh well, we don't - * make the situation any worse by proceeding as if it had succeeded. - */ - mem_cgroup_charge(new, mm, GFP_ATOMIC); - get_page(new); pte = pte_mkold(mk_pte(new, vma->vm_page_prot)); if (is_write_migration_entry(entry)) @@ -378,9 +364,6 @@ static void migrate_page_copy(struct page *newpage, struct page *page) anon = PageAnon(page); page->mapping = NULL; - if (!anon) /* This page was removed from radix-tree. */ - mem_cgroup_uncharge_cache_page(page); - /* * If any waiters have accumulated on the new page then * wake them up. @@ -614,6 +597,7 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private, struct page *newpage = get_new_page(page, private, &result); int rcu_locked = 0; int charge = 0; + struct mem_cgroup *mem; if (!newpage) return -ENOMEM; @@ -623,24 +607,26 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private, goto move_newpage; } - charge = mem_cgroup_prepare_migration(page, newpage); - if (charge == -ENOMEM) { - rc = -ENOMEM; - goto move_newpage; - } /* prepare cgroup just returns 0 or -ENOMEM */ - BUG_ON(charge); - rc = -EAGAIN; + if (!trylock_page(page)) { if (!force) goto move_newpage; lock_page(page); } + /* charge against new page */ + charge = mem_cgroup_prepare_migration(page, &mem); + if (charge == -ENOMEM) { + rc = -ENOMEM; + goto unlock; + } + BUG_ON(charge); + if (PageWriteback(page)) { if (!force) - goto unlock; + goto uncharge; wait_on_page_writeback(page); } /* @@ -693,7 +679,9 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private, rcu_unlock: if (rcu_locked) rcu_read_unlock(); - +uncharge: + if (!charge) + mem_cgroup_end_migration(mem, page, newpage); unlock: unlock_page(page); @@ -709,8 +697,6 @@ unlock: } move_newpage: - if (!charge) - mem_cgroup_end_migration(newpage); /* * Move the new page to the LRU. If migration was not successful |