Merge Christoph's freeze cleanup patch

1 files changed, 59 insertions, 14 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 98c109e..9530b19 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1265,33 +1265,78 @@ extern void normalize_rt_tasks(void);
 
 #endif
 
-/* try_to_freeze
- *
- * Checks whether we need to enter the refrigerator
- * and returns 1 if we did so.
- */
 #ifdef CONFIG_PM
-extern void refrigerator(unsigned long);
+/*
+ * Check if a process has been frozen
+ */
+static inline int frozen(struct task_struct *p)
+{
+	return p->flags & PF_FROZEN;
+}
+
+/*
+ * Check if there is a request to freeze a process
+ */
+static inline int freezing(struct task_struct *p)
+{
+	return p->flags & PF_FREEZE;
+}
+
+/*
+ * Request that a process be frozen
+ * FIXME: SMP problem. We may not modify other process' flags!
+ */
+static inline void freeze(struct task_struct *p)
+{
+	p->flags |= PF_FREEZE;
+}
+
+/*
+ * Wake up a frozen process
+ */
+static inline int thaw_process(struct task_struct *p)
+{
+	if (frozen(p)) {
+		p->flags &= ~PF_FROZEN;
+		wake_up_process(p);
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * freezing is complete, mark process as frozen
+ */
+static inline void frozen_process(struct task_struct *p)
+{
+	p->flags = (p->flags & ~PF_FREEZE) | PF_FROZEN;
+}
+
+extern void refrigerator(void);
 extern int freeze_processes(void);
 extern void thaw_processes(void);
 
-static inline int try_to_freeze(unsigned long refrigerator_flags)
+static inline int try_to_freeze(void)
 {
-	if (unlikely(current->flags & PF_FREEZE)) {
-		refrigerator(refrigerator_flags);
+	if (freezing(current)) {
+		refrigerator();
 		return 1;
 	} else
 		return 0;
 }
 #else
-static inline void refrigerator(unsigned long flag) {}
+static inline int frozen(struct task_struct *p) { return 0; }
+static inline int freezing(struct task_struct *p) { return 0; }
+static inline void freeze(struct task_struct *p) { BUG(); }
+static inline int thaw_process(struct task_struct *p) { return 1; }
+static inline void frozen_process(struct task_struct *p) { BUG(); }
+
+static inline void refrigerator(void) {}
 static inline int freeze_processes(void) { BUG(); return 0; }
 static inline void thaw_processes(void) {}
 
-static inline int try_to_freeze(unsigned long refrigerator_flags)
-{
-	return 0;
-}
+static inline int try_to_freeze(void) { return 0; }
+
 #endif /* CONFIG_PM */
 #endif /* __KERNEL__ */