Now that the TIF_FREEZE flag is available in all architectures, extract the refrigerator() and freeze_task() from kernel/power/process.c and make it available to all. The refrigerator() can now be used in a control group subsystem implementing a control group freezer. Signed-off-by: Cedric Le Goater <clg@xxxxxxxxxx> Signed-off-by: Matt Helsley <matthltc@xxxxxxxxxx> Tested-by: Matt Helsley <matthltc@xxxxxxxxxx> Cc: linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx --- Changelog: Merged Roland's "STOPPED is frozen enough" changes. For details see: http://lkml.org/lkml/2008/3/3/676 include/linux/freezer.h | 19 ++----- kernel/Makefile | 2 kernel/freezer.c | 124 ++++++++++++++++++++++++++++++++++++++++++++++++ kernel/power/process.c | 113 ------------------------------------------- 4 files changed, 132 insertions(+), 126 deletions(-) Index: linux-2.6.25-rc8-mm1/include/linux/freezer.h =================================================================== --- linux-2.6.25-rc8-mm1.orig/include/linux/freezer.h +++ linux-2.6.25-rc8-mm1/include/linux/freezer.h @@ -4,11 +4,10 @@ #define FREEZER_H_INCLUDED #include <linux/sched.h> #include <linux/wait.h> -#ifdef CONFIG_PM_SLEEP /* * Check if a process has been frozen */ static inline int frozen(struct task_struct *p) { @@ -61,22 +60,27 @@ static inline int thaw_process(struct ta task_unlock(p); return 0; } extern void refrigerator(void); -extern int freeze_processes(void); -extern void thaw_processes(void); static inline int try_to_freeze(void) { if (freezing(current)) { refrigerator(); return 1; } else return 0; } +extern int freeze_task(struct task_struct *p, int with_mm_only); + +#ifdef CONFIG_PM_SLEEP + +extern int freeze_processes(void); +extern void thaw_processes(void); + /* * 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 @@ -156,22 +160,13 @@ static inline void set_freezable(void) __retval); \ } while (try_to_freeze()); \ __retval; \ }) #else /* !CONFIG_PM_SLEEP */ -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 void refrigerator(void) {} static inline int freeze_processes(void) { BUG(); return 0; } static inline void thaw_processes(void) {} -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) {} Index: linux-2.6.25-rc8-mm1/kernel/Makefile =================================================================== --- linux-2.6.25-rc8-mm1.orig/kernel/Makefile +++ linux-2.6.25-rc8-mm1/kernel/Makefile @@ -7,11 +7,11 @@ obj-y = sched.o fork.o exec_domain.o sysctl.o capability.o ptrace.o timer.o user.o \ signal.o sys.o kmod.o workqueue.o pid.o \ rcupdate.o extable.o params.o posix-timers.o \ kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \ hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \ - notifier.o ksysfs.o pm_qos_params.o + notifier.o ksysfs.o pm_qos_params.o freezer.o obj-$(CONFIG_SYSCTL_SYSCALL_CHECK) += sysctl_check.o obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-y += time/ obj-$(CONFIG_DEBUG_MUTEXES) += mutex-debug.o Index: linux-2.6.25-rc8-mm1/kernel/freezer.c =================================================================== --- /dev/null +++ linux-2.6.25-rc8-mm1/kernel/freezer.c @@ -0,0 +1,124 @@ +/* + * 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); +} + +static int has_mm(struct task_struct *p) +{ + return (p->mm && !(p->flags & PF_BORROWED_MM)); +} + +/** + * freeze_task - send a freeze request to given task + * @p: task to send the request to + * @with_mm_only: if set, the request will only be sent if the task has its + * own mm + * Return value: 0, if @with_mm_only is set and the task has no mm of its + * own or the task is frozen, 1, otherwise + * + * The freeze request is sent by seting 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 its own mm (ie. it is a user land task). If @with_mm_only + * is set and the task has no mm of its own (ie. it is a kernel thread), + * its TIF_FREEZE flag should not be set. + * + * The task_lock() is necessary to prevent races with exit_mm() or + * use_mm()/unuse_mm() from occuring. + */ +int freeze_task(struct task_struct *p, int with_mm_only) +{ + int ret = 1; + + task_lock(p); + if (freezing(p)) { + if (has_mm(p)) { + if (!signal_pending(p)) + fake_signal_wake_up(p); + } else { + if (with_mm_only) + ret = 0; + else + wake_up_state(p, TASK_INTERRUPTIBLE); + } + } else { + rmb(); + if (frozen(p)) { + ret = 0; + } else { + if (has_mm(p)) { + set_freeze_flag(p); + fake_signal_wake_up(p); + } else { + if (with_mm_only) { + ret = 0; + } else { + set_freeze_flag(p); + wake_up_state(p, TASK_INTERRUPTIBLE); + } + } + } + } + task_unlock(p); + return ret; +} Index: linux-2.6.25-rc8-mm1/kernel/power/process.c =================================================================== --- linux-2.6.25-rc8-mm1.orig/kernel/power/process.c +++ linux-2.6.25-rc8-mm1/kernel/power/process.c @@ -29,121 +29,10 @@ static inline int freezeable(struct task (p->exit_state != 0)) return 0; 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 int has_mm(struct task_struct *p) -{ - return (p->mm && !(p->flags & PF_BORROWED_MM)); -} - -/** - * freeze_task - send a freeze request to given task - * @p: task to send the request to - * @with_mm_only: if set, the request will only be sent if the task has its - * own mm - * Return value: 0, if @with_mm_only is set and the task has no mm of its - * own or the task is frozen, 1, otherwise - * - * The freeze request is sent by seting 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 its own mm (ie. it is a user land task). If @with_mm_only - * is set and the task has no mm of its own (ie. it is a kernel thread), - * its TIF_FREEZE flag should not be set. - * - * The task_lock() is necessary to prevent races with exit_mm() or - * use_mm()/unuse_mm() from occuring. - */ -static int freeze_task(struct task_struct *p, int with_mm_only) -{ - int ret = 1; - - task_lock(p); - if (freezing(p)) { - if (has_mm(p)) { - if (!signal_pending(p)) - fake_signal_wake_up(p); - } else { - if (with_mm_only) - ret = 0; - else - wake_up_state(p, TASK_INTERRUPTIBLE); - } - } else { - rmb(); - if (frozen(p)) { - ret = 0; - } else { - if (has_mm(p)) { - set_freeze_flag(p); - fake_signal_wake_up(p); - } else { - if (with_mm_only) { - ret = 0; - } else { - set_freeze_flag(p); - wake_up_state(p, TASK_INTERRUPTIBLE); - } - } - } - } - task_unlock(p); - return ret; -} static void cancel_freezing(struct task_struct *p) { unsigned long flags; @@ -274,7 +163,5 @@ void thaw_processes(void) thaw_tasks(FREEZER_KERNEL_THREADS); thaw_tasks(FREEZER_USER_SPACE); schedule(); printk("done.\n"); } - -EXPORT_SYMBOL(refrigerator); -- _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
