1 files changed, 74 insertions, 0 deletions
diff --git a/tools/testing/selftests/sched_ext/enq_select_cpu.bpf.c b/tools/testing/selftests/sched_ext/enq_select_cpu.bpf.c
new file mode 100644
index 000000000000..ee2c9b89716e
--- /dev/null
+++ b/tools/testing/selftests/sched_ext/enq_select_cpu.bpf.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2023 Meta Platforms, Inc. and affiliates.
+ * Copyright (c) 2023 David Vernet <dvernet@meta.com>
+ * Copyright (c) 2023 Tejun Heo <tj@kernel.org>
+ */
+
+#include <scx/common.bpf.h>
+
+char _license[] SEC("license") = "GPL";
+
+UEI_DEFINE(uei);
+
+s32 BPF_STRUCT_OPS(enq_select_cpu_select_cpu, struct task_struct *p,
+		   s32 prev_cpu, u64 wake_flags)
+{
+	/* Bounce all tasks to ops.enqueue() */
+	return prev_cpu;
+}
+
+void BPF_STRUCT_OPS(enq_select_cpu_enqueue, struct task_struct *p,
+		    u64 enq_flags)
+{
+	s32 cpu, prev_cpu = scx_bpf_task_cpu(p);
+	bool found = false;
+
+	cpu = scx_bpf_select_cpu_dfl(p, prev_cpu, 0, &found);
+	if (found) {
+		scx_bpf_dsq_insert(p, SCX_DSQ_LOCAL_ON | cpu, SCX_SLICE_DFL, enq_flags);
+		return;
+	}
+
+	scx_bpf_dsq_insert(p, SCX_DSQ_GLOBAL, SCX_SLICE_DFL, enq_flags);
+}
+
+void BPF_STRUCT_OPS(enq_select_cpu_exit, struct scx_exit_info *ei)
+{
+	UEI_RECORD(uei, ei);
+}
+
+struct task_cpu_arg {
+	pid_t pid;
+};
+
+SEC("syscall")
+int select_cpu_from_user(struct task_cpu_arg *input)
+{
+	struct task_struct *p;
+	bool found = false;
+	s32 cpu;
+
+	p = bpf_task_from_pid(input->pid);
+	if (!p)
+		return -EINVAL;
+
+	bpf_rcu_read_lock();
+	cpu = scx_bpf_select_cpu_dfl(p, bpf_get_smp_processor_id(), 0, &found);
+	if (!found)
+		cpu = -EBUSY;
+	bpf_rcu_read_unlock();
+
+	bpf_task_release(p);
+
+	return cpu;
+}
+
+SEC(".struct_ops.link")
+struct sched_ext_ops enq_select_cpu_ops = {
+	.select_cpu		= (void *)enq_select_cpu_select_cpu,
+	.enqueue		= (void *)enq_select_cpu_enqueue,
+	.exit			= (void *)enq_select_cpu_exit,
+	.name			= "enq_select_cpu",
+	.timeout_ms		= 1000U,
+};