[Intel-gfx] [PATCH CI 1/2] Revert "freezer, sched: Rewrite core freezer logic fix"

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

This reverts commit f3387d5883ad92e9a54306fa3dff97d4f0581d78.
---
 kernel/sched/core.c | 49 ++++++++++++++++-----------------------------
 1 file changed, 17 insertions(+), 32 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index f519f44cd4c7..cb2aa2b54c7a 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4200,37 +4200,6 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
 	return success;
 }
 
-static bool __task_needs_rq_lock(struct task_struct *p)
-{
-	unsigned int state = READ_ONCE(p->__state);
-
-	/*
-	 * Since pi->lock blocks try_to_wake_up(), we don't need rq->lock when
-	 * the task is blocked. Make sure to check @state since ttwu() can drop
-	 * locks at the end, see ttwu_queue_wakelist().
-	 */
-	if (state == TASK_RUNNING || state == TASK_WAKING)
-		return true;
-
-	/*
-	 * Ensure we load p->on_rq after p->__state, otherwise it would be
-	 * possible to, falsely, observe p->on_rq == 0.
-	 *
-	 * See try_to_wake_up() for a longer comment.
-	 */
-	smp_rmb();
-	if (p->on_rq)
-		return true;
-
-#ifdef CONFIG_SMP
-	smp_rmb();
-	if (p->on_cpu)
-		return true;
-#endif
-
-	return false;
-}
-
 /**
  * task_call_func - Invoke a function on task in fixed state
  * @p: Process for which the function is to be invoked, can be @current.
@@ -4248,12 +4217,28 @@ static bool __task_needs_rq_lock(struct task_struct *p)
 int task_call_func(struct task_struct *p, task_call_f func, void *arg)
 {
 	struct rq *rq = NULL;
+	unsigned int state;
 	struct rq_flags rf;
 	int ret;
 
 	raw_spin_lock_irqsave(&p->pi_lock, rf.flags);
 
-	if (__task_needs_rq_lock(p))
+	state = READ_ONCE(p->__state);
+
+	/*
+	 * Ensure we load p->on_rq after p->__state, otherwise it would be
+	 * possible to, falsely, observe p->on_rq == 0.
+	 *
+	 * See try_to_wake_up() for a longer comment.
+	 */
+	smp_rmb();
+
+	/*
+	 * Since pi->lock blocks try_to_wake_up(), we don't need rq->lock when
+	 * the task is blocked. Make sure to check @state since ttwu() can drop
+	 * locks at the end, see ttwu_queue_wakelist().
+	 */
+	if (state == TASK_RUNNING || state == TASK_WAKING || p->on_rq)
 		rq = __task_rq_lock(p, &rf);
 
 	/*
-- 
2.37.4