sched: Split up put_prev_task_balance()

With the goal of pushing put_prev_task() after pick_task() / into
pick_next_task().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240813224015.943143811@infradead.org

kernel/sched/core.c

@@ -5841,8 +5841,8 @@ static inline void schedule_debug(struct task_struct *prev, bool preempt)
 	schedstat_inc(this_rq()->sched_count);
 }
 
-static void put_prev_task_balance(struct rq *rq, struct task_struct *prev,
-				  struct rq_flags *rf)
+static void prev_balance(struct rq *rq, struct task_struct *prev,
+			 struct rq_flags *rf)
 {
 #ifdef CONFIG_SMP
 	const struct sched_class *class;
@@ -5860,8 +5860,6 @@ static void put_prev_task_balance(struct rq *rq, struct task_struct *prev,
 	}
 #endif
 
-	put_prev_task(rq, prev);
-
 	/*
 	 * We've updated @prev and no longer need the server link, clear it.
 	 * Must be done before ->pick_next_task() because that can (re)set
@@ -5917,7 +5915,8 @@ __pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 	}
 
 restart:
-	put_prev_task_balance(rq, prev, rf);
+	prev_balance(rq, prev, rf);
+	put_prev_task(rq, prev);
 
 	for_each_class(class) {
 		p = class->pick_next_task(rq);
@@ -6017,7 +6016,8 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 		goto out;
 	}
 
-	put_prev_task_balance(rq, prev, rf);
+	prev_balance(rq, prev, rf);
+	put_prev_task(rq, prev);
 
 	smt_mask = cpu_smt_mask(cpu);
 	need_sync = !!rq->core->core_cookie;