/* Freezer declarations */
-#ifdef CONFIG_PM
+#ifndef FREEZER_H_INCLUDED
+#define FREEZER_H_INCLUDED
+
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+#ifdef CONFIG_FREEZER
/*
* Check if a process has been frozen
*/
*/
static inline int freezing(struct task_struct *p)
{
- return p->flags & PF_FREEZE;
+ return test_tsk_thread_flag(p, TIF_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)
+static inline void set_freeze_flag(struct task_struct *p)
{
- p->flags |= PF_FREEZE;
+ set_tsk_thread_flag(p, TIF_FREEZE);
}
/*
* Sometimes we may need to cancel the previous 'freeze' request
*/
-static inline void do_not_freeze(struct task_struct *p)
+static inline void clear_freeze_flag(struct task_struct *p)
{
- p->flags &= ~PF_FREEZE;
+ clear_tsk_thread_flag(p, TIF_FREEZE);
}
-/*
- * Wake up a frozen process
- */
-static inline int thaw_process(struct task_struct *p)
+static inline bool should_send_signal(struct task_struct *p)
{
- if (frozen(p)) {
- p->flags &= ~PF_FROZEN;
- wake_up_process(p);
- return 1;
- }
- return 0;
+ return !(p->flags & PF_FREEZER_NOSIG);
}
-/*
- * freezing is complete, mark process as frozen
- */
-static inline void frozen_process(struct task_struct *p)
-{
- p->flags = (p->flags & ~PF_FREEZE) | PF_FROZEN;
-}
+/* 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);
return 0;
}
-extern void thaw_some_processes(int all);
+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
+ * function. Next, the parent should call try_to_freeze() to freeze itself
+ * appropriately in case the child has exited before the freezing of tasks is
+ * complete. However, we don't want kernel threads to be frozen in unexpected
+ * places, so we allow them to block freeze_processes() instead or to set
+ * PF_NOFREEZE if needed and PF_FREEZER_SKIP is only set for userland vfork
+ * parents. Fortunately, in the ____call_usermodehelper() case the parent won't
+ * really block freeze_processes(), since ____call_usermodehelper() (the child)
+ * does a little before exec/exit and it can't be frozen before waking up the
+ * parent.
+ */
+
+/*
+ * If the current task is a user space one, tell the freezer not to count it as
+ * freezable.
+ */
+static inline void freezer_do_not_count(void)
+{
+ if (current->mm)
+ current->flags |= PF_FREEZER_SKIP;
+}
+
+/*
+ * If the current task is a user space one, tell the freezer to count it as
+ * freezable again and try to freeze it.
+ */
+static inline void freezer_count(void)
+{
+ if (current->mm) {
+ current->flags &= ~PF_FREEZER_SKIP;
+ try_to_freeze();
+ }
+}
+
+/*
+ * Check if the task should be counted as freezeable by the freezer
+ */
+static inline int freezer_should_skip(struct task_struct *p)
+{
+ return !!(p->flags & PF_FREEZER_SKIP);
+}
+
+/*
+ * Tell the freezer that the current task should be frozen by it
+ */
+static inline void set_freezable(void)
+{
+ current->flags &= ~PF_NOFREEZE;
+}
+
+/*
+ * Tell the freezer that the current task should be frozen by it and that it
+ * should send a fake signal to the task to freeze it.
+ */
+static inline void set_freezable_with_signal(void)
+{
+ current->flags &= ~(PF_NOFREEZE | PF_FREEZER_NOSIG);
+}
+
+/*
+ * Freezer-friendly wrappers around wait_event_interruptible() and
+ * wait_event_interruptible_timeout(), originally defined in <linux/wait.h>
+ */
+
+#define wait_event_freezable(wq, condition) \
+({ \
+ int __retval; \
+ do { \
+ __retval = wait_event_interruptible(wq, \
+ (condition) || freezing(current)); \
+ if (__retval && !freezing(current)) \
+ break; \
+ else if (!(condition)) \
+ __retval = -ERESTARTSYS; \
+ } while (try_to_freeze()); \
+ __retval; \
+})
+
-#else
+#define wait_event_freezable_timeout(wq, condition, timeout) \
+({ \
+ long __retval = timeout; \
+ do { \
+ __retval = wait_event_interruptible_timeout(wq, \
+ (condition) || freezing(current), \
+ __retval); \
+ } while (try_to_freeze()); \
+ __retval; \
+})
+#else /* !CONFIG_FREEZER */
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 void set_freeze_flag(struct task_struct *p) {}
+static inline void clear_freeze_flag(struct task_struct *p) {}
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 int try_to_freeze(void) { return 0; }
+static inline void freezer_do_not_count(void) {}
+static inline void freezer_count(void) {}
+static inline int freezer_should_skip(struct task_struct *p) { return 0; }
+static inline void set_freezable(void) {}
+static inline void set_freezable_with_signal(void) {}
+
+#define wait_event_freezable(wq, condition) \
+ wait_event_interruptible(wq, condition)
+
+#define wait_event_freezable_timeout(wq, condition, timeout) \
+ wait_event_interruptible_timeout(wq, condition, timeout)
+
+#endif /* !CONFIG_FREEZER */
-#endif
+#endif /* FREEZER_H_INCLUDED */
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