diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/freezer.h | 48 | ||||
| -rw-r--r-- | include/linux/sched.h | 1 |
2 files changed, 47 insertions, 2 deletions
diff --git a/include/linux/freezer.h b/include/linux/freezer.h index db5423eae24..c9435252e8e 100644 --- a/include/linux/freezer.h +++ b/include/linux/freezer.h @@ -81,7 +81,49 @@ static inline int try_to_freeze(void) return 0; } -extern void thaw_some_processes(int all); +/* + * 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); +} #else static inline int frozen(struct task_struct *p) { return 0; } @@ -96,5 +138,7 @@ 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; } #endif diff --git a/include/linux/sched.h b/include/linux/sched.h index a81897e2a24..870b75e348a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1182,6 +1182,7 @@ static inline void put_task_struct(struct task_struct *t) #define PF_SPREAD_SLAB 0x02000000 /* Spread some slab caches over cpuset */ #define PF_MEMPOLICY 0x10000000 /* Non-default NUMA mempolicy */ #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */ +#define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezeable */ /* * Only the _current_ task can read/write to tsk->flags, but other |