From 4bb6f4ea50ecfaed76049e40f81705df47369085 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 13 Dec 2011 21:42:19 +0100 Subject: [134/254] sched: ttwu: Return success when only changing the saved_state value When a task blocks on a rt lock, it saves the current state in p->saved_state, so a lock related wake up will not destroy the original state. When a real wakeup happens, while the task is running due to a lock wakeup already, we update p->saved_state to TASK_RUNNING, but we do not return success, which might cause another wakeup in the waitqueue code and the task remains in the waitqueue list. Return success in that case as well. Signed-off-by: Thomas Gleixner Cc: stable-rt@vger.kernel.org --- kernel/sched/core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 9bc29c2..ea45f8b 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1593,8 +1593,10 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) * if the wakeup condition is true. */ if (!(wake_flags & WF_LOCK_SLEEPER)) { - if (p->saved_state & state) + if (p->saved_state & state) { p->saved_state = TASK_RUNNING; + success = 1; + } } goto out; }