[PATCH v6 2/5] exit: hoist get_pid() in release_task() outside of tasklist_lock

From: Mateusz Guzik
Date: Thu Feb 06 2025 - 11:44:55 EST


Reduces hold time as get_pid() contains an atomic.

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

diff --git a/kernel/exit.c b/kernel/exit.c
index 9d7acd7b0040..8c39c84582b7 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