diff options
Diffstat (limited to 'include/linux/freezer.h')
| -rw-r--r-- | include/linux/freezer.h | 159 |
1 files changed, 76 insertions, 83 deletions
diff --git a/include/linux/freezer.h b/include/linux/freezer.h index a5386e3ee75..0ab54e16a91 100644 --- a/include/linux/freezer.h +++ b/include/linux/freezer.h @@ -5,71 +5,58 @@ #include <linux/sched.h> #include <linux/wait.h> +#include <linux/atomic.h> #ifdef CONFIG_FREEZER +extern atomic_t system_freezing_cnt; /* nr of freezing conds in effect */ +extern bool pm_freezing; /* PM freezing in effect */ +extern bool pm_nosig_freezing; /* PM nosig freezing in effect */ + /* * Check if a process has been frozen */ -static inline int frozen(struct task_struct *p) +static inline bool 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 test_tsk_thread_flag(p, TIF_FREEZE); -} - -/* - * Request that a process be frozen - */ -static inline void set_freeze_flag(struct task_struct *p) -{ - set_tsk_thread_flag(p, TIF_FREEZE); -} +extern bool freezing_slow_path(struct task_struct *p); /* - * Sometimes we may need to cancel the previous 'freeze' request + * Check if there is a request to freeze a process */ -static inline void clear_freeze_flag(struct task_struct *p) -{ - clear_tsk_thread_flag(p, TIF_FREEZE); -} - -static inline bool should_send_signal(struct task_struct *p) +static inline bool freezing(struct task_struct *p) { - return !(p->flags & PF_FREEZER_NOSIG); + if (likely(!atomic_read(&system_freezing_cnt))) + return false; + return freezing_slow_path(p); } /* Takes and releases task alloc lock using task_lock() */ -extern int thaw_process(struct task_struct *p); +extern void __thaw_task(struct task_struct *t); -extern void refrigerator(void); +extern bool __refrigerator(bool check_kthr_stop); extern int freeze_processes(void); extern int freeze_kernel_threads(void); extern void thaw_processes(void); -static inline int try_to_freeze(void) +static inline bool try_to_freeze(void) { - if (freezing(current)) { - refrigerator(); - return 1; - } else - return 0; + might_sleep(); + if (likely(!freezing(current))) + return false; + return __refrigerator(false); } -extern bool freeze_task(struct task_struct *p, bool sig_only); -extern void cancel_freezing(struct task_struct *p); +extern bool freeze_task(struct task_struct *p); +extern bool set_freezable(void); #ifdef CONFIG_CGROUP_FREEZER -extern int cgroup_freezing_or_frozen(struct task_struct *task); +extern bool cgroup_freezing(struct task_struct *task); #else /* !CONFIG_CGROUP_FREEZER */ -static inline int cgroup_freezing_or_frozen(struct task_struct *task) +static inline bool cgroup_freezing(struct task_struct *task) { - return 0; + return false; } #endif /* !CONFIG_CGROUP_FREEZER */ @@ -80,33 +67,27 @@ static inline int cgroup_freezing_or_frozen(struct task_struct *task) * 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. + * PF_NOFREEZE if needed. 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. - */ + +/* Tell the freezer not to count the current task as freezable. */ static inline void freezer_do_not_count(void) { - if (current->mm) - current->flags |= PF_FREEZER_SKIP; + 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. + * Tell the freezer to count the current task 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(); - } + current->flags &= ~PF_FREEZER_SKIP; + try_to_freeze(); } /* @@ -118,21 +99,29 @@ static inline int freezer_should_skip(struct task_struct *p) } /* - * Tell the freezer that the current task should be frozen by it + * These macros are intended to be used whenever you want allow a task that's + * sleeping in TASK_UNINTERRUPTIBLE or TASK_KILLABLE state to be frozen. Note + * that neither return any clear indication of whether a freeze event happened + * while in this function. */ -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); -} +/* Like schedule(), but should not block the freezer. */ +#define freezable_schedule() \ +({ \ + freezer_do_not_count(); \ + schedule(); \ + freezer_count(); \ +}) + +/* Like schedule_timeout_killable(), but should not block the freezer. */ +#define freezable_schedule_timeout_killable(timeout) \ +({ \ + long __retval; \ + freezer_do_not_count(); \ + __retval = schedule_timeout_killable(timeout); \ + freezer_count(); \ + __retval; \ +}) /* * Freezer-friendly wrappers around wait_event_interruptible(), @@ -152,47 +141,51 @@ static inline void set_freezable_with_signal(void) #define wait_event_freezable(wq, condition) \ ({ \ int __retval; \ - do { \ + for (;;) { \ __retval = wait_event_interruptible(wq, \ (condition) || freezing(current)); \ - if (__retval && !freezing(current)) \ + if (__retval || (condition)) \ break; \ - else if (!(condition)) \ - __retval = -ERESTARTSYS; \ - } while (try_to_freeze()); \ + try_to_freeze(); \ + } \ __retval; \ }) - #define wait_event_freezable_timeout(wq, condition, timeout) \ ({ \ long __retval = timeout; \ - do { \ + for (;;) { \ __retval = wait_event_interruptible_timeout(wq, \ (condition) || freezing(current), \ __retval); \ - } while (try_to_freeze()); \ + if (__retval <= 0 || (condition)) \ + break; \ + 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 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 bool frozen(struct task_struct *p) { return false; } +static inline bool freezing(struct task_struct *p) { return false; } +static inline void __thaw_task(struct task_struct *t) {} -static inline void refrigerator(void) {} +static inline bool __refrigerator(bool check_kthr_stop) { return false; } static inline int freeze_processes(void) { return -ENOSYS; } static inline int freeze_kernel_threads(void) { return -ENOSYS; } static inline void thaw_processes(void) {} -static inline int try_to_freeze(void) { return 0; } +static inline bool try_to_freeze(void) { return false; } 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 freezable_schedule() schedule() + +#define freezable_schedule_timeout_killable(timeout) \ + schedule_timeout_killable(timeout) #define wait_event_freezable(wq, condition) \ wait_event_interruptible(wq, condition) |