Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[pandora-kernel.git] / mm / migrate.c

diff --git a/mm/migrate.c b/mm/migrate.c
index 0a75716..2bb4e1d 100644 (file)
--- 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))
@@ -300,12 +286,10 @@ static int migrate_page_move_mapping(struct address_space *mapping,
         * Now we know that no one else is looking at the page.
         */
        get_page(newpage);      /* add cache reference */
-#ifdef CONFIG_SWAP
        if (PageSwapCache(page)) {
                SetPageSwapCache(newpage);
                set_page_private(newpage, page_private(page));
        }
-#endif
 
        radix_tree_replace_slot(pslot, newpage);
 
@@ -373,18 +357,13 @@ static void migrate_page_copy(struct page *newpage, struct page *page)
 
        mlock_migrate_page(newpage, page);
 
-#ifdef CONFIG_SWAP
        ClearPageSwapCache(page);
-#endif
        ClearPagePrivate(page);
        set_page_private(page, 0);
        /* page->mapping contains a flag for PageAnon() */
        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.
@@ -618,6 +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;
@@ -627,24 +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);
        }
        /*
@@ -697,7 +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);
 
@@ -713,8 +697,6 @@ unlock:
        }
 
 move_newpage:
-       if (!charge)
-               mem_cgroup_end_migration(newpage);
 
        /*
         * Move the new page to the LRU. If migration was not successful
@@ -848,12 +830,6 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
                struct vm_area_struct *vma;
                struct page *page;
 
-               /*
-                * A valid page pointer that will not match any of the
-                * pages that will be moved.
-                */
-               pp->page = ZERO_PAGE(0);
-
                err = -EFAULT;
                vma = find_vma(mm, pp->addr);
                if (!vma || !vma_migratable(vma))
@@ -1079,10 +1055,10 @@ out:
  * Move a list of pages in the address space of the currently executing
  * process.
  */
-asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages,
-                       const void __user * __user *pages,
-                       const int __user *nodes,
-                       int __user *status, int flags)
+SYSCALL_DEFINE6(move_pages, pid_t, pid, unsigned long, nr_pages,
+               const void __user * __user *, pages,
+               const int __user *, nodes,
+               int __user *, status, int, flags)
 {
        const struct cred *cred = current_cred(), *tcred;
        struct task_struct *task;