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
13 char _license[] SEC("license") = "GPL";
14
15 bool saw_local = false;
16
task_is_test(const struct task_struct * p)17 static bool task_is_test(const struct task_struct *p)
18 {
19 return !bpf_strncmp(p->comm, 9, "select_cpu");
20 }
21
BPF_STRUCT_OPS(select_cpu_dfl_enqueue,struct task_struct * p,u64 enq_flags)22 void 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
36 SEC(".struct_ops.link")
37 struct sched_ext_ops select_cpu_dfl_ops = {
38 .enqueue = (void *) select_cpu_dfl_enqueue,
39 .name = "select_cpu_dfl",
40 };
41