xref: /linux/tools/testing/selftests/sched_ext/exit.c (revision bf61759db409ce21a8f2a5bb442b7c35905a713d)
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 #include <bpf/bpf.h>
7 #include <sched.h>
8 #include <scx/common.h>
9 #include <sys/wait.h>
10 #include <unistd.h>
11 #include "exit.bpf.skel.h"
12 #include "scx_test.h"
13 
14 #include "exit_test.h"
15 
run(void * ctx)16 static enum scx_test_status run(void *ctx)
17 {
18 	enum exit_test_case tc;
19 
20 	for (tc = 0; tc < NUM_EXITS; tc++) {
21 		struct exit *skel;
22 		struct bpf_link *link;
23 		char buf[16];
24 
25 		/*
26 		 * On single-CPU systems, ops.select_cpu() is never
27 		 * invoked, so skip this test to avoid getting stuck
28 		 * indefinitely.
29 		 */
30 		if (tc == EXIT_SELECT_CPU && libbpf_num_possible_cpus() == 1)
31 			continue;
32 
33 		skel = exit__open();
34 		SCX_ENUM_INIT(skel);
35 		skel->rodata->exit_point = tc;
36 		exit__load(skel);
37 		link = bpf_map__attach_struct_ops(skel->maps.exit_ops);
38 		if (!link) {
39 			SCX_ERR("Failed to attach scheduler");
40 			exit__destroy(skel);
41 			return SCX_TEST_FAIL;
42 		}
43 
44 		/* Assumes uei.kind is written last */
45 		while (skel->data->uei.kind == EXIT_KIND(SCX_EXIT_NONE))
46 			sched_yield();
47 
48 		SCX_EQ(skel->data->uei.kind, EXIT_KIND(SCX_EXIT_UNREG_BPF));
49 		SCX_EQ(skel->data->uei.exit_code, tc);
50 		sprintf(buf, "%d", tc);
51 		SCX_ASSERT(!strcmp(skel->data->uei.msg, buf));
52 		bpf_link__destroy(link);
53 		exit__destroy(skel);
54 	}
55 
56 	return SCX_TEST_PASS;
57 }
58 
59 struct scx_test exit_test = {
60 	.name = "exit",
61 	.description = "Verify we can cleanly exit a scheduler in multiple places",
62 	.run = run,
63 };
64 REGISTER_SCX_TEST(&exit_test)
65