tools/testing/selftests/sched_ext/select_cpu_dfl.bpf.c

   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
  17 static bool task_is_test(const struct task_struct *p)
  18 {
  19         return !bpf_strncmp(p->comm, 9, "select_cpu");
  20 }
  21
  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_dispatch(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 };