1 files changed, 64 insertions, 2 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d8c963fea9eb..6042ce3bfee0 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3791,6 +3791,15 @@ bool cpus_share_resources(int this_cpu, int that_cpu)
 static inline bool ttwu_queue_cond(struct task_struct *p, int cpu)
 {
 	/*
+	 * The BPF scheduler may depend on select_task_rq() being invoked during
+	 * wakeups. In addition, @p may end up executing on a different CPU
+	 * regardless of what happens in the wakeup path making the ttwu_queue
+	 * optimization less meaningful. Skip if on SCX.
+	 */
+	if (task_on_scx(p))
+		return false;
+
+	/*
 	 * Do not complicate things with the async wake_list while the CPU is
 	 * in hotplug state.
 	 */
@@ -4357,6 +4366,10 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
 	p->rt.on_rq		= 0;
 	p->rt.on_list		= 0;
 
+#ifdef CONFIG_SCHED_CLASS_EXT
+	init_scx_entity(&p->scx);
+#endif
+
 #ifdef CONFIG_PREEMPT_NOTIFIERS
 	INIT_HLIST_HEAD(&p->preempt_notifiers);
 #endif
@@ -4604,6 +4617,10 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p)
 		goto out_cancel;
 	} else if (rt_prio(p->prio)) {
 		p->sched_class = &rt_sched_class;
+#ifdef CONFIG_SCHED_CLASS_EXT
+	} else if (task_should_scx(p)) {
+		p->sched_class = &ext_sched_class;
+#endif
 	} else {
 		p->sched_class = &fair_sched_class;
 	}
@@ -5511,8 +5528,10 @@ void sched_tick(void)
 		wq_worker_tick(curr);
 
 #ifdef CONFIG_SMP
-	rq->idle_balance = idle_cpu(cpu);
-	sched_balance_trigger(rq);
+	if (!scx_switched_all()) {
+		rq->idle_balance = idle_cpu(cpu);
+		sched_balance_trigger(rq);
+	}
 #endif
 }
 
@@ -6902,6 +6921,10 @@ void __setscheduler_prio(struct task_struct *p, int prio)
 		p->sched_class = &dl_sched_class;
 	else if (rt_prio(prio))
 		p->sched_class = &rt_sched_class;
+#ifdef CONFIG_SCHED_CLASS_EXT
+	else if (task_should_scx(p))
+		p->sched_class = &ext_sched_class;
+#endif
 	else
 		p->sched_class = &fair_sched_class;
 
@@ -8203,6 +8226,10 @@ void __init sched_init(void)
 	BUG_ON(!sched_class_above(&dl_sched_class, &rt_sched_class));
 	BUG_ON(!sched_class_above(&rt_sched_class, &fair_sched_class));
 	BUG_ON(!sched_class_above(&fair_sched_class, &idle_sched_class));
+#ifdef CONFIG_SCHED_CLASS_EXT
+	BUG_ON(!sched_class_above(&fair_sched_class, &ext_sched_class));
+	BUG_ON(!sched_class_above(&ext_sched_class, &idle_sched_class));
+#endif
 
 	wait_bit_init();
 
@@ -10337,3 +10364,38 @@ void sched_mm_cid_fork(struct task_struct *t)
 	t->mm_cid_active = 1;
 }
 #endif
+
+#ifdef CONFIG_SCHED_CLASS_EXT
+void sched_deq_and_put_task(struct task_struct *p, int queue_flags,
+			    struct sched_enq_and_set_ctx *ctx)
+{
+	struct rq *rq = task_rq(p);
+
+	lockdep_assert_rq_held(rq);
+
+	*ctx = (struct sched_enq_and_set_ctx){
+		.p = p,
+		.queue_flags = queue_flags,
+		.queued = task_on_rq_queued(p),
+		.running = task_current(rq, p),
+	};
+
+	update_rq_clock(rq);
+	if (ctx->queued)
+		dequeue_task(rq, p, queue_flags | DEQUEUE_NOCLOCK);
+	if (ctx->running)
+		put_prev_task(rq, p);
+}
+
+void sched_enq_and_set_task(struct sched_enq_and_set_ctx *ctx)
+{
+	struct rq *rq = task_rq(ctx->p);
+
+	lockdep_assert_rq_held(rq);
+
+	if (ctx->queued)
+		enqueue_task(rq, ctx->p, ctx->queue_flags | ENQUEUE_NOCLOCK);
+	if (ctx->running)
+		set_next_task(rq, ctx->p);
+}
+#endif	/* CONFIG_SCHED_CLASS_EXT */