xref: /linux/tools/testing/selftests/sched_ext/hotplug.bpf.c (revision fcb3ad4366b9c810cbb9da34c076a9a52d8aa1e0)
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  */
6 
7 #include <scx/common.bpf.h>
8 
9 char _license[] SEC("license") = "GPL";
10 
11 #include "hotplug_test.h"
12 
13 UEI_DEFINE(uei);
14 
15 void BPF_STRUCT_OPS(hotplug_exit, struct scx_exit_info *ei)
16 {
17 	UEI_RECORD(uei, ei);
18 }
19 
20 static void exit_from_hotplug(s32 cpu, bool onlining)
21 {
22 	/*
23 	 * Ignored, just used to verify that we can invoke blocking kfuncs
24 	 * from the hotplug path.
25 	 */
26 	scx_bpf_create_dsq(0, -1);
27 
28 	s64 code = SCX_ECODE_ACT_RESTART | HOTPLUG_EXIT_RSN;
29 
30 	if (onlining)
31 		code |= HOTPLUG_ONLINING;
32 
33 	scx_bpf_exit(code, "hotplug event detected (%d going %s)", cpu,
34 		     onlining ? "online" : "offline");
35 }
36 
37 void BPF_STRUCT_OPS_SLEEPABLE(hotplug_cpu_online, s32 cpu)
38 {
39 	exit_from_hotplug(cpu, true);
40 }
41 
42 void BPF_STRUCT_OPS_SLEEPABLE(hotplug_cpu_offline, s32 cpu)
43 {
44 	exit_from_hotplug(cpu, false);
45 }
46 
47 SEC(".struct_ops.link")
48 struct sched_ext_ops hotplug_cb_ops = {
49 	.cpu_online		= (void *) hotplug_cpu_online,
50 	.cpu_offline		= (void *) hotplug_cpu_offline,
51 	.exit			= (void *) hotplug_exit,
52 	.name			= "hotplug_cbs",
53 	.timeout_ms		= 1000U,
54 };
55 
56 SEC(".struct_ops.link")
57 struct sched_ext_ops hotplug_nocb_ops = {
58 	.exit			= (void *) hotplug_exit,
59 	.name			= "hotplug_nocbs",
60 	.timeout_ms		= 1000U,
61 };
62