diff options
| -rw-r--r-- | include/linux/freezer.h | 14 | ||||
| -rw-r--r-- | kernel/Makefile | 1 | ||||
| -rw-r--r-- | kernel/freezer.c | 122 | ||||
| -rw-r--r-- | kernel/power/Kconfig | 3 | ||||
| -rw-r--r-- | kernel/power/process.c | 116 |
5 files changed, 137 insertions, 119 deletions
diff --git a/include/linux/freezer.h b/include/linux/freezer.h index deddeed..17e3bb4 100644 --- a/include/linux/freezer.h +++ b/include/linux/freezer.h @@ -6,7 +6,7 @@ #include <linux/sched.h> #include <linux/wait.h> -#ifdef CONFIG_PM_SLEEP +#ifdef CONFIG_FREEZER /* * Check if a process has been frozen */ @@ -39,6 +39,11 @@ 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) +{ + return !(p->flags & PF_FREEZER_NOSIG); +} + /* * Wake up a frozen process * @@ -75,6 +80,9 @@ static inline int try_to_freeze(void) return 0; } +extern bool freeze_task(struct task_struct *p, bool sig_only); +extern void cancel_freezing(struct task_struct *p); + /* * 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 @@ -166,7 +174,7 @@ static inline void set_freezable_with_signal(void) } while (try_to_freeze()); \ __retval; \ }) -#else /* !CONFIG_PM_SLEEP */ +#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) {} @@ -191,6 +199,6 @@ static inline void set_freezable_with_signal(void) {} #define wait_event_freezable_timeout(wq, condition, timeout) \ wait_event_interruptible_timeout(wq, condition, timeout) -#endif /* !CONFIG_PM_SLEEP */ +#endif /* !CONFIG_FREEZER */ #endif /* FREEZER_H_INCLUDED */ diff --git a/kernel/Makefile b/kernel/Makefile index 4e1d7df..e8194d1 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -24,6 +24,7 @@ CFLAGS_REMOVE_sched_clock.o = -pg CFLAGS_REMOVE_sched.o = -mno-spe -pg endif +obj-$(CONFIG_FREEZER) += freezer.o obj-$(CONFIG_PROFILING) += profile.o obj-$(CONFIG_SYSCTL_SYSCALL_CHECK) += sysctl_check.o obj-$(CONFIG_STACKTRACE) += stacktrace.o diff --git a/kernel/freezer.c b/kernel/freezer.c new file mode 100644 index 0000000..cb0931f --- /dev/null +++ b/kernel/freezer.c @@ -0,0 +1,122 @@ +/* + * kernel/freezer.c - Function to freeze a process + * + * Originally from kernel/power/process.c + */ + +#include <linux/interrupt.h> +#include <linux/suspend.h> +#include <linux/module.h> +#include <linux/syscalls.h> +#include <linux/freezer.h> + +/* + * freezing is complete, mark current process as frozen + */ +static inline void frozen_process(void) +{ + if (!unlikely(current->flags & PF_NOFREEZE)) { + current->flags |= PF_FROZEN; + wmb(); + } + clear_freeze_flag(current); +} + +/* Refrigerator is place where frozen processes are stored :-). */ +void refrigerator(void) +{ + /* Hmm, should we be allowed to suspend when there are realtime + processes around? */ + long save; + + task_lock(current); + if (freezing(current)) { + frozen_process(); + task_unlock(current); + } else { + task_unlock(current); + return; + } + save = current->state; + pr_debug("%s entered refrigerator\n", current->comm); + + spin_lock_irq(¤t->sighand->siglock); + recalc_sigpending(); /* We sent fake signal, clean it up */ + spin_unlock_irq(¤t->sighand->siglock); + + for (;;) { + set_current_state(TASK_UNINTERRUPTIBLE); + if (!frozen(current)) + break; + schedule(); + } + pr_debug("%s left refrigerator\n", current->comm); + __set_current_state(save); +} +EXPORT_SYMBOL(refrigerator); + +static void fake_signal_wake_up(struct task_struct *p) +{ + unsigned long flags; + + spin_lock_irqsave(&p->sighand->siglock, flags); + signal_wake_up(p, 0); + spin_unlock_irqrestore(&p->sighand->siglock, flags); +} + +/** + * freeze_task - send a freeze request to given task + * @p: task to send the request to + * @sig_only: if set, the request will only be sent if the task has the + * PF_FREEZER_NOSIG flag unset + * Return value: 'false', if @sig_only is set and the task has + * PF_FREEZER_NOSIG set or the task is frozen, 'true', otherwise + * + * The freeze request is sent by setting the tasks's TIF_FREEZE flag and + * either sending a fake signal to it or waking it up, depending on whether + * or not it has PF_FREEZER_NOSIG set. If @sig_only is set and the task + * has PF_FREEZER_NOSIG set (ie. it is a typical kernel thread), its + * TIF_FREEZE flag will not be set. + */ +bool freeze_task(struct task_struct *p, bool sig_only) +{ + /* + * We first check if the task is freezing and next if it has already + * been frozen to avoid the race with frozen_process() which first marks + * the task as frozen and next clears its TIF_FREEZE. + */ + if (!freezing(p)) { + rmb(); + if (frozen(p)) + return false; + + if (!sig_only || should_send_signal(p)) + set_freeze_flag(p); + else + return false; + } + + if (should_send_signal(p)) { + if (!signal_pending(p)) + fake_signal_wake_up(p); + } else if (sig_only) { + return false; + } else { + wake_up_state(p, TASK_INTERRUPTIBLE); + } + + return true; +} + +void cancel_freezing(struct task_struct *p) +{ + unsigned long flags; + + if (freezing(p)) { + pr_debug(" clean up: %s\n", p->comm); + clear_freeze_flag(p); + spin_lock_irqsave(&p->sighand->siglock, flags); + recalc_sigpending_and_wake(p); + spin_unlock_irqrestore(&p->sighand->siglock, flags); + } +} diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index dcd165f..ebdd7f5 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -85,6 +85,9 @@ config PM_SLEEP depends on SUSPEND || HIBERNATION || XEN_SAVE_RESTORE default y +config FREEZER + def_bool PM_SLEEP + config SUSPEND bool "Suspend to RAM and standby" depends on PM && ARCH_SUSPEND_POSSIBLE diff --git a/kernel/power/process.c b/kernel/power/process.c index 278946a..444cea8 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -28,121 +28,6 @@ static inline int freezeable(struct task_struct * p) return 1; } -/* - * freezing is complete, mark current process as frozen - */ -static inline void frozen_process(void) -{ - if (!unlikely(current->flags & PF_NOFREEZE)) { - current->flags |= PF_FROZEN; - wmb(); - } - clear_freeze_flag(current); -} - -/* Refrigerator is place where frozen processes are stored :-). */ -void refrigerator(void) -{ - /* Hmm, should we be allowed to suspend when there are realtime - processes around? */ - long save; - - task_lock(current); - if (freezing(current)) { - frozen_process(); - task_unlock(current); - } else { - task_unlock(current); - return; - } - save = current->state; - pr_debug("%s entered refrigerator\n", current->comm); - - spin_lock_irq(¤t->sighand->siglock); - recalc_sigpending(); /* We sent fake signal, clean it up */ - spin_unlock_irq(¤t->sighand->siglock); - - for (;;) { - set_current_state(TASK_UNINTERRUPTIBLE); - if (!frozen(current)) - break; - schedule(); - } - pr_debug("%s left refrigerator\n", current->comm); - __set_current_state(save); -} - -static void fake_signal_wake_up(struct task_struct *p) -{ - unsigned long flags; - - spin_lock_irqsave(&p->sighand->siglock, flags); - signal_wake_up(p, 0); - spin_unlock_irqrestore(&p->sighand->siglock, flags); -} - -static inline bool should_send_signal(struct task_struct *p) -{ - return !(p->flags & PF_FREEZER_NOSIG); -} - -/** - * freeze_task - send a freeze request to given task - * @p: task to send the request to - * @sig_only: if set, the request will only be sent if the task has the - * PF_FREEZER_NOSIG flag unset - * Return value: 'false', if @sig_only is set and the task has - * PF_FREEZER_NOSIG set or the task is frozen, 'true', otherwise - * - * The freeze request is sent by setting the tasks's TIF_FREEZE flag and - * either sending a fake signal to it or waking it up, depending on whether - * or not it has PF_FREEZER_NOSIG set. If @sig_only is set and the task - * has PF_FREEZER_NOSIG set (ie. it is a typical kernel thread), its - * TIF_FREEZE flag will not be set. - */ -static bool freeze_task(struct task_struct *p, bool sig_only) -{ - /* - * We first check if the task is freezing and next if it has already - * been frozen to avoid the race with frozen_process() which first marks - * the task as frozen and next clears its TIF_FREEZE. - */ - if (!freezing(p)) { - rmb(); - if (frozen(p)) - return false; - - if (!sig_only || should_send_signal(p)) - set_freeze_flag(p); - else - return false; - } - - if (should_send_signal(p)) { - if (!signal_pending(p)) - fake_signal_wake_up(p); - } else if (sig_only) { - return false; - } else { - wake_up_state(p, TASK_INTERRUPTIBLE); - } - - return true; -} - -static void cancel_freezing(struct task_struct *p) -{ - unsigned long flags; - - if (freezing(p)) { - pr_debug(" clean up: %s\n", p->comm); - clear_freeze_flag(p); - spin_lock_irqsave(&p->sighand->siglock, flags); - recalc_sigpending_and_wake(p); - spin_unlock_irqrestore(&p->sighand->siglock, flags); - } -} - static int try_to_freeze_tasks(bool sig_only) { struct task_struct *g, *p; @@ -264,4 +149,3 @@ void thaw_processes(void) printk("done.\n"); } -EXPORT_SYMBOL(refrigerator); |
