diff options
| -rw-r--r-- | include/linux/sched.h | 2 | ||||
| -rw-r--r-- | kernel/exit.c | 1 | ||||
| -rw-r--r-- | kernel/sched/auto_group.c | 19 |
3 files changed, 22 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 348f51b0ec92..e9c009dc3a4a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2567,6 +2567,7 @@ extern void sched_autogroup_create_attach(struct task_struct *p); extern void sched_autogroup_detach(struct task_struct *p); extern void sched_autogroup_fork(struct signal_struct *sig); extern void sched_autogroup_exit(struct signal_struct *sig); +extern void sched_autogroup_exit_task(struct task_struct *p); #ifdef CONFIG_PROC_FS extern void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m); extern int proc_sched_autogroup_set_nice(struct task_struct *p, int nice); @@ -2576,6 +2577,7 @@ static inline void sched_autogroup_create_attach(struct task_struct *p) { } static inline void sched_autogroup_detach(struct task_struct *p) { } static inline void sched_autogroup_fork(struct signal_struct *sig) { } static inline void sched_autogroup_exit(struct signal_struct *sig) { } +static inline void sched_autogroup_exit_task(struct task_struct *p) { } #endif extern int yield_to(struct task_struct *p, bool preempt); diff --git a/kernel/exit.c b/kernel/exit.c index 9d68c45ebbe3..3076f3089919 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -836,6 +836,7 @@ void __noreturn do_exit(long code) */ perf_event_exit_task(tsk); + sched_autogroup_exit_task(tsk); cgroup_exit(tsk); /* diff --git a/kernel/sched/auto_group.c b/kernel/sched/auto_group.c index ad2b19ad6ca0..f1c8fd566246 100644 --- a/kernel/sched/auto_group.c +++ b/kernel/sched/auto_group.c @@ -115,10 +115,26 @@ bool task_wants_autogroup(struct task_struct *p, struct task_group *tg) * If we race with autogroup_move_group() the caller can use the old * value of signal->autogroup but in this case sched_move_task() will * be called again before autogroup_kref_put(). + * + * However, there is no way sched_autogroup_exit_task() could tell us + * to avoid autogroup->tg, so we abuse PF_EXITING flag for this case. */ + if (p->flags & PF_EXITING) + return false; + return true; } +void sched_autogroup_exit_task(struct task_struct *p) +{ + /* + * We are going to call exit_notify() and autogroup_move_group() can't + * see this thread after that: we can no longer use signal->autogroup. + * See the PF_EXITING check in task_wants_autogroup(). + */ + sched_move_task(p); +} + static void autogroup_move_group(struct task_struct *p, struct autogroup *ag) { @@ -142,6 +158,9 @@ autogroup_move_group(struct task_struct *p, struct autogroup *ag) * In the latter case for_each_thread() can not miss a migrating thread, * cpu_cgroup_attach() must not be possible after cgroup_exit() and it * can't be removed from thread list, we hold ->siglock. + * + * If an exiting thread was already removed from thread list we rely on + * sched_autogroup_exit_task(). */ for_each_thread(p, t) sched_move_task(t); |