1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (c) 2024 Meta Platforms, Inc. and affiliates.
4 * Copyright (c) 2024 David Vernet <dvernet@meta.com>
5 * Copyright (c) 2024 Tejun Heo <tj@kernel.org>
6 */
7 #include <scx/common.bpf.h>
8
9 char _license[] SEC("license") = "GPL";
10
11 UEI_DEFINE(uei);
12
BPF_STRUCT_OPS(ddsp_bogus_dsq_fail_select_cpu,struct task_struct * p,s32 prev_cpu,u64 wake_flags)13 s32 BPF_STRUCT_OPS(ddsp_bogus_dsq_fail_select_cpu, struct task_struct *p,
14 s32 prev_cpu, u64 wake_flags)
15 {
16 s32 cpu = scx_bpf_pick_idle_cpu(p->cpus_ptr, 0);
17
18 if (cpu >= 0) {
19 /*
20 * If we dispatch to a bogus DSQ that will fall back to the
21 * builtin global DSQ, we fail gracefully.
22 */
23 scx_bpf_dispatch_vtime(p, 0xcafef00d, SCX_SLICE_DFL,
24 p->scx.dsq_vtime, 0);
25 return cpu;
26 }
27
28 return prev_cpu;
29 }
30
BPF_STRUCT_OPS(ddsp_bogus_dsq_fail_exit,struct scx_exit_info * ei)31 void BPF_STRUCT_OPS(ddsp_bogus_dsq_fail_exit, struct scx_exit_info *ei)
32 {
33 UEI_RECORD(uei, ei);
34 }
35
36 SEC(".struct_ops.link")
37 struct sched_ext_ops ddsp_bogus_dsq_fail_ops = {
38 .select_cpu = (void *) ddsp_bogus_dsq_fail_select_cpu,
39 .exit = (void *) ddsp_bogus_dsq_fail_exit,
40 .name = "ddsp_bogus_dsq_fail",
41 .timeout_ms = 1000U,
42 };
43