[RFC] decrease tsk->signal->live before profile_task_exit

From: liuchao
Date: Wed May 27 2020 - 23:44:00 EST


I want to dermine which thread is the last one to enter
do_exit in profile_task_exit. But when a lot of threads
exit, tsk->signal->live is not correct since it decrease
after profile_task_exit.

Signed-off-by: liuchao <liuchao173@xxxxxxxxxx>
---
kernel/exit.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/exit.c b/kernel/exit.c
index ce2a75bc0ade..1693764bc356 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -708,6 +708,7 @@ void __noreturn do_exit(long code)
struct task_struct *tsk = current;
int group_dead;

+ group_dead = atomic_dec_and_test(&tsk->signal->live);
profile_task_exit(tsk);
kcov_task_exit(tsk);

@@ -755,7 +756,6 @@ void __noreturn do_exit(long code)
if (tsk->mm)
sync_mm_rss(tsk->mm);
acct_update_integrals(tsk);
- group_dead = atomic_dec_and_test(&tsk->signal->live);
if (group_dead) {
/*
* If the last thread of global init has exited, panic
--
2.19.1