cgroup: Call cgroup_release() before __exit_signal()
cgroup_release() calls cgroup_subsys->release() which is used by the
pids controller to uncharge its pid. We want to use it to manage
iteration of dying tasks which requires putting it before
__unhash_process(). Move cgroup_release() above __exit_signal().
While this makes it uncharge before the pid is freed, pid is RCU freed
anyway and the window is very narrow.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
diff --git a/kernel/exit.c b/kernel/exit.c
index 1803efb..a75b6a7 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -195,6 +195,7 @@ void release_task(struct task_struct *p)
rcu_read_unlock();
proc_flush_task(p);
+ cgroup_release(p);
write_lock_irq(&tasklist_lock);
ptrace_release_task(p);
@@ -220,7 +221,6 @@ void release_task(struct task_struct *p)
}
write_unlock_irq(&tasklist_lock);
- cgroup_release(p);
release_thread(p);
call_rcu(&p->rcu, delayed_put_task_struct);