1/* SPDX-License-Identifier: GPL-2.0 */
 2/*
 3 * A scheduler that validates the behavior of direct dispatching with a default
 4 * select_cpu implementation.
 5 *
 6 * Copyright (c) 2023 Meta Platforms, Inc. and affiliates.
 7 * Copyright (c) 2023 David Vernet <dvernet@meta.com>
 8 * Copyright (c) 2023 Tejun Heo <tj@kernel.org>
 9 */
10
11#include <scx/common.bpf.h>
12
13char _license[] SEC("license") = "GPL";
14
15bool saw_local = false;
16
17static bool task_is_test(const struct task_struct *p)
18{
19	return !bpf_strncmp(p->comm, 9, "select_cpu");
20}
21
22void BPF_STRUCT_OPS(select_cpu_dfl_enqueue, struct task_struct *p,
23		    u64 enq_flags)
24{
25	const struct cpumask *idle_mask = scx_bpf_get_idle_cpumask();
26
27	if (task_is_test(p) &&
28	    bpf_cpumask_test_cpu(scx_bpf_task_cpu(p), idle_mask)) {
29		saw_local = true;
30	}
31	scx_bpf_put_idle_cpumask(idle_mask);
32
33	scx_bpf_dsq_insert(p, SCX_DSQ_GLOBAL, SCX_SLICE_DFL, enq_flags);
34}
35
36SEC(".struct_ops.link")
37struct sched_ext_ops select_cpu_dfl_ops = {
38	.enqueue		= (void *) select_cpu_dfl_enqueue,
39	.name			= "select_cpu_dfl",
40};