ANDROID: sched: move blocked reason trace point to cover all class

Now, we only export CFS taks' blocked reasons but it's
important and useful to know other class' blocked
reasons such as RT tasks.

Move the blocked reason trace point to where the scheduler
core layer and before the task's state moves to the waking
state. Thus, we could cover all the sched classes.

Bug: 203080186
Test: check traces
Signed-off-by: Martin Liu <liumartin@google.com>
Change-Id: Ic61865642d852d0127cdcf474adf8c06e4c2d570

kernel/sched/core.c

@@ -3116,6 +3116,9 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
 	if (READ_ONCE(p->on_rq) && ttwu_runnable(p, wake_flags))
 		goto unlock;
 
+	if (p->state & TASK_UNINTERRUPTIBLE)
+		trace_sched_blocked_reason(p);
+
 #ifdef CONFIG_SMP
 	/*
 	 * Ensure we load p->on_cpu _after_ p->on_rq, otherwise it would be

kernel/sched/fair.c

@@ -999,7 +999,6 @@ update_stats_enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
 			}
 
 			trace_sched_stat_blocked(tsk, delta);
-			trace_sched_blocked_reason(tsk);
 
 			/*
 			 * Blocking time is in units of nanosecs, so shift by