Merge branch 'akpm' (patches from Andrew)

Merge second set of updates from Andrew Morton:
 "More of MM"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (83 commits)
  mm/nommu.c: fix arithmetic overflow in __vm_enough_memory()
  mm/mmap.c: fix arithmetic overflow in __vm_enough_memory()
  vmstat: Reduce time interval to stat update on idle cpu
  mm/page_owner.c: remove unnecessary stack_trace field
  Documentation/filesystems/proc.txt: describe /proc/<pid>/map_files
  mm: incorporate read-only pages into transparent huge pages
  vmstat: do not use deferrable delayed work for vmstat_update
  mm: more aggressive page stealing for UNMOVABLE allocations
  mm: always steal split buddies in fallback allocations
  mm: when stealing freepages, also take pages created by splitting buddy page
  mincore: apply page table walker on do_mincore()
  mm: /proc/pid/clear_refs: avoid split_huge_page()
  mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP)
  mempolicy: apply page table walker on queue_pages_range()
  arch/powerpc/mm/subpage-prot.c: use walk->vma and walk_page_vma()
  memcg: cleanup preparation for page table walk
  numa_maps: remove numa_maps->vma
  numa_maps: fix typo in gather_hugetbl_stats
  pagemap: use walk->vma instead of calling find_vma()
  clear_refs: remove clear_refs_private->vma and introduce clear_refs_test_walk()
  ...

kernel/exit.c

@@ -435,7 +435,8 @@ static void exit_mm(struct task_struct *tsk)
 	task_unlock(tsk);
 	mm_update_next_owner(mm);
 	mmput(mm);
-	clear_thread_flag(TIF_MEMDIE);
+	if (test_thread_flag(TIF_MEMDIE))
+		unmark_oom_victim();
 }
 
 static struct task_struct *find_alive_thread(struct task_struct *p)

kernel/fork.c

@@ -555,6 +555,9 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p)
 	INIT_LIST_HEAD(&mm->mmlist);
 	mm->core_state = NULL;
 	atomic_long_set(&mm->nr_ptes, 0);
+#ifndef __PAGETABLE_PMD_FOLDED
+	atomic_long_set(&mm->nr_pmds, 0);
+#endif
 	mm->map_count = 0;
 	mm->locked_vm = 0;
 	mm->pinned_vm = 0;
@@ -603,6 +606,14 @@ static void check_mm(struct mm_struct *mm)
 			printk(KERN_ALERT "BUG: Bad rss-counter state "
 					  "mm:%p idx:%d val:%ld\n", mm, i, x);
 	}
+
+	if (atomic_long_read(&mm->nr_ptes))
+		pr_alert("BUG: non-zero nr_ptes on freeing mm: %ld\n",
+				atomic_long_read(&mm->nr_ptes));
+	if (mm_nr_pmds(mm))
+		pr_alert("BUG: non-zero nr_pmds on freeing mm: %ld\n",
+				mm_nr_pmds(mm));
+
 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
 	VM_BUG_ON_MM(mm->pmd_huge_pte, mm);
 #endif

kernel/power/process.c

@@ -84,8 +84,8 @@ static int try_to_freeze_tasks(bool user_only)
 	elapsed_msecs = elapsed_msecs64;
 
 	if (todo) {
-		printk("\n");
-		printk(KERN_ERR "Freezing of tasks %s after %d.%03d seconds "
+		pr_cont("\n");
+		pr_err("Freezing of tasks %s after %d.%03d seconds "
 		       "(%d tasks refusing to freeze, wq_busy=%d):\n",
 		       wakeup ? "aborted" : "failed",
 		       elapsed_msecs / 1000, elapsed_msecs % 1000,
@@ -101,37 +101,13 @@ static int try_to_freeze_tasks(bool user_only)
 			read_unlock(&tasklist_lock);
 		}
 	} else {
-		printk("(elapsed %d.%03d seconds) ", elapsed_msecs / 1000,
+		pr_cont("(elapsed %d.%03d seconds) ", elapsed_msecs / 1000,
 			elapsed_msecs % 1000);
 	}
 
 	return todo ? -EBUSY : 0;
 }
 
-static bool __check_frozen_processes(void)
-{
-	struct task_struct *g, *p;
-
-	for_each_process_thread(g, p)
-		if (p != current && !freezer_should_skip(p) && !frozen(p))
-			return false;
-
-	return true;
-}
-
-/*
- * Returns true if all freezable tasks (except for current) are frozen already
- */
-static bool check_frozen_processes(void)
-{
-	bool ret;
-
-	read_lock(&tasklist_lock);
-	ret = __check_frozen_processes();
-	read_unlock(&tasklist_lock);
-	return ret;
-}
-
 /**
  * freeze_processes - Signal user space processes to enter the refrigerator.
  * The current thread will not be frozen.  The same process that calls
@@ -142,7 +118,6 @@ static bool check_frozen_processes(void)
 int freeze_processes(void)
 {
 	int error;
-	int oom_kills_saved;
 
 	error = __usermodehelper_disable(UMH_FREEZING);
 	if (error)
@@ -155,31 +130,24 @@ int freeze_processes(void)
 		atomic_inc(&system_freezing_cnt);
 
 	pm_wakeup_clear();
-	printk("Freezing user space processes ... ");
+	pr_info("Freezing user space processes ... ");
 	pm_freezing = true;
-	oom_kills_saved = oom_kills_count();
 	error = try_to_freeze_tasks(true);
 	if (!error) {
 		__usermodehelper_set_disable_depth(UMH_DISABLED);
-		oom_killer_disable();
-
-		/*
-		 * There might have been an OOM kill while we were
-		 * freezing tasks and the killed task might be still
-		 * on the way out so we have to double check for race.
-		 */
-		if (oom_kills_count() != oom_kills_saved &&
-		    !check_frozen_processes()) {
-			__usermodehelper_set_disable_depth(UMH_ENABLED);
-			printk("OOM in progress.");
-			error = -EBUSY;
-		} else {
-			printk("done.");
-		}
+		pr_cont("done.");
 	}
-	printk("\n");
+	pr_cont("\n");
 	BUG_ON(in_atomic());
 
+	/*
+	 * Now that the whole userspace is frozen we need to disbale
+	 * the OOM killer to disallow any further interference with
+	 * killable tasks.
+	 */
+	if (!error && !oom_killer_disable())
+		error = -EBUSY;
+
 	if (error)
 		thaw_processes();
 	return error;
@@ -197,13 +165,14 @@ int freeze_kernel_threads(void)
 {
 	int error;
 
-	printk("Freezing remaining freezable tasks ... ");
+	pr_info("Freezing remaining freezable tasks ... ");
+
 	pm_nosig_freezing = true;
 	error = try_to_freeze_tasks(false);
 	if (!error)
-		printk("done.");
+		pr_cont("done.");
 
-	printk("\n");
+	pr_cont("\n");
 	BUG_ON(in_atomic());
 
 	if (error)
@@ -224,7 +193,7 @@ void thaw_processes(void)
 
 	oom_killer_enable();
 
-	printk("Restarting tasks ... ");
+	pr_info("Restarting tasks ... ");
 
 	__usermodehelper_set_disable_depth(UMH_FREEZING);
 	thaw_workqueues();
@@ -243,7 +212,7 @@ void thaw_processes(void)
 	usermodehelper_enable();
 
 	schedule();
-	printk("done.\n");
+	pr_cont("done.\n");
 	trace_suspend_resume(TPS("thaw_processes"), 0, false);
 }
 
@@ -252,7 +221,7 @@ void thaw_kernel_threads(void)
 	struct task_struct *g, *p;
 
 	pm_nosig_freezing = false;
-	printk("Restarting kernel threads ... ");
+	pr_info("Restarting kernel threads ... ");
 
 	thaw_workqueues();
 
@@ -264,5 +233,5 @@ void thaw_kernel_threads(void)
 	read_unlock(&tasklist_lock);
 
 	schedule();
-	printk("done.\n");
+	pr_cont("done.\n");
 }