2 files changed, 16 insertions, 19 deletions

diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
index e2877454ec82..9c22396e8b50 100644
--- a/include/linux/cgroup_subsys.h
+++ b/include/linux/cgroup_subsys.h
@@ -48,3 +48,9 @@ SUBSYS(devices)
 #endif
 
 /* */
+
+#ifdef CONFIG_CGROUP_FREEZER
+SUBSYS(freezer)
+#endif
+
+/* */
diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index 17e3bb42dd3c..8f225339eee9 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -46,26 +46,11 @@ static inline bool should_send_signal(struct task_struct *p)
 
 /*
  * Wake up a frozen process
- *
- * task_lock() is taken to prevent the race with refrigerator() which may
- * occur if the freezing of tasks fails.  Namely, without the lock, if the
- * freezing of tasks failed, thaw_tasks() might have run before a task in
- * refrigerator() could call frozen_process(), in which case the task would be
- * frozen and no one would thaw it.
  */
-static inline int thaw_process(struct task_struct *p)
-{
-        task_lock(p);
-        if (frozen(p)) {
-                p->flags &= ~PF_FROZEN;
-                task_unlock(p);
-                wake_up_process(p);
-                return 1;
-        }
-        clear_freeze_flag(p);
-        task_unlock(p);
-        return 0;
-}
+extern int __thaw_process(struct task_struct *p);
+
+/* Takes and releases task alloc lock using task_lock() */
+extern int thaw_process(struct task_struct *p);
 
 extern void refrigerator(void);
 extern int freeze_processes(void);
@@ -83,6 +68,12 @@ static inline int try_to_freeze(void)
 extern bool freeze_task(struct task_struct *p, bool sig_only);
 extern void cancel_freezing(struct task_struct *p);
 
+#ifdef CONFIG_CGROUP_FREEZER
+extern int cgroup_frozen(struct task_struct *task);
+#else /* !CONFIG_CGROUP_FREEZER */
+static inline int cgroup_frozen(struct task_struct *task) { return 0; }
+#endif /* !CONFIG_CGROUP_FREEZER */
+
 /*
  * The PF_FREEZER_SKIP flag should be set by a vfork parent right before it
  * calls wait_for_completion(&vfork) and reset right after it returns from this