2012-02-20 17:31:37

by Alexander Gordeev

[permalink] [raw]
Subject: [PATCH 3/5] genirq: No need to check IRQTF_DIED before stopping a thread handler

Since 63706172f332fd3f6e7458ebfb35fa6de9c21dc5 kthread_stop() is not
afraid of dead kernel threads. So no need to check if a thread is
alive before stopping it. These checks still were racy.

Reported-by: Oleg Nesterov <[email protected]>
Signed-off-by: Alexander Gordeev <[email protected]>
---
kernel/irq/manage.c | 6 ++----
1 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 0fa3ce9..3feab4a 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1106,8 +1106,7 @@ out_thread:
struct task_struct *t = new->thread;

new->thread = NULL;
- if (likely(!test_bit(IRQTF_DIED, &new->thread_flags)))
- kthread_stop(t);
+ kthread_stop(t);
put_task_struct(t);
}
out_mput:
@@ -1217,8 +1216,7 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
#endif

if (action->thread) {
- if (!test_bit(IRQTF_DIED, &action->thread_flags))
- kthread_stop(action->thread);
+ kthread_stop(action->thread);
put_task_struct(action->thread);
}

--
1.7.7.6