reduces hold time as get_pid() contains an atomic

Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
---
 kernel/exit.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/exit.c b/kernel/exit.c
index c79b41509cd3..b5c0cbc6bdfb 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -248,9 +248,10 @@ void release_task(struct task_struct *p)
 
 	cgroup_release(p);
 
+	thread_pid = get_pid(p->thread_pid);
+
 	write_lock_irq(&tasklist_lock);
 	ptrace_release_task(p);
-	thread_pid = get_pid(p->thread_pid);
 	__exit_signal(p);
 
 	/*
-- 
2.43.0