diff options
| author | San Mehat <san@google.com> | 2011-12-13 01:08:18 +0800 |
|---|---|---|
| committer | Andy Green <andy.green@linaro.org> | 2012-01-09 10:26:39 +0800 |
| commit | 5b196f64ebe07624d44eadb5e0ea72f8dd2e22cc (patch) | |
| tree | 163bd57f12b8ecee9f5de09a5622c81e9410ea5c | |
| parent | c97c51cfafe6ba958dff7417e6e880cd48863928 (diff) | |
sched: Add a generic notifier when a task struct is about to be freedlinaro-androidization-topic-sched
This patch adds a notifier which can be used by subsystems that may
be interested in when a task has completely died and is about to
have it's last resource freed.
The Android lowmemory killer uses this to determine when a task
it has killed has finally given up its goods.
Signed-off-by: San Mehat <san@google.com>
| -rw-r--r-- | include/linux/sched.h | 3 | ||||
| -rw-r--r-- | kernel/fork.c | 16 |
2 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 1c4f3e9b9bc..653c9c3799b 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1756,6 +1756,9 @@ static inline void put_task_struct(struct task_struct *t) extern void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st); extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st); +extern int task_free_register(struct notifier_block *n); +extern int task_free_unregister(struct notifier_block *n); + /* * Per process flags */ diff --git a/kernel/fork.c b/kernel/fork.c index da4a6a10d08..69c2e4ce3a3 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -153,6 +153,9 @@ struct kmem_cache *vm_area_cachep; /* SLAB cache for mm_struct structures (tsk->mm) */ static struct kmem_cache *mm_cachep; +/* Notifier list called when a task struct is freed */ +static ATOMIC_NOTIFIER_HEAD(task_free_notifier); + static void account_kernel_stack(struct thread_info *ti, int account) { struct zone *zone = page_zone(virt_to_page(ti)); @@ -183,6 +186,18 @@ static inline void put_signal_struct(struct signal_struct *sig) free_signal_struct(sig); } +int task_free_register(struct notifier_block *n) +{ + return atomic_notifier_chain_register(&task_free_notifier, n); +} +EXPORT_SYMBOL(task_free_register); + +int task_free_unregister(struct notifier_block *n) +{ + return atomic_notifier_chain_unregister(&task_free_notifier, n); +} +EXPORT_SYMBOL(task_free_unregister); + void __put_task_struct(struct task_struct *tsk) { WARN_ON(!tsk->exit_state); @@ -193,6 +208,7 @@ void __put_task_struct(struct task_struct *tsk) delayacct_tsk_free(tsk); put_signal_struct(tsk->signal); + atomic_notifier_call_chain(&task_free_notifier, 0, tsk); if (!profile_handoff_task(tsk)) free_task(tsk); } |