[PATCH 4/5] wait: completely ignore the EXIT_DEAD tasks

[Oleg Nesterov <oleg@redhat.com>]

Now that EXIT_DEAD is the terminal state it doesn't make sense
to call eligible_child() or security_task_wait() if the task is
really dead.

Tested-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 kernel/exit.c |   11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/kernel/exit.c b/kernel/exit.c
index aaad08d..3d6f247 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1331,7 +1331,12 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p)
 static int wait_consider_task(struct wait_opts *wo, int ptrace,
 				struct task_struct *p)
 {
-	int ret = eligible_child(wo, p);
+	int ret;
+
+	if (unlikely(p->exit_state == EXIT_DEAD))
+		return 0;
+
+	ret = eligible_child(wo, p);
 	if (!ret)
 		return ret;
 
@@ -1349,10 +1354,6 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace,
 		return 0;
 	}
 
-	/* dead body doesn't have much to contribute */
-	if (unlikely(p->exit_state == EXIT_DEAD))
-		return 0;
-
 	if (unlikely(p->exit_state == EXIT_TRACE)) {
 		/*
 		 * ptrace == 0 means we are the natural parent. In this case
-- 
1.5.5.1