xref: /linux/tools/testing/selftests/sched_ext/exit.c (revision 11260c335ec6071af5543aef73000b28f041c124)
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_FAIL_IF(!skel, "Failed to open");
35 		SCX_ENUM_INIT(skel);
36 		skel->rodata->exit_point = tc;
37 		SCX_FAIL_IF(exit__load(skel), "Failed to load skel");
38 		link = bpf_map__attach_struct_ops(skel->maps.exit_ops);
39 		if (!link) {
40 			SCX_ERR("Failed to attach scheduler");
41 			exit__destroy(skel);
42 			return SCX_TEST_FAIL;
43 		}
44 
45 		/* Assumes uei.kind is written last */
46 		while (skel->data->uei.kind == EXIT_KIND(SCX_EXIT_NONE))
47 			sched_yield();
48 
49 		SCX_EQ(skel->data->uei.kind, EXIT_KIND(SCX_EXIT_UNREG_BPF));
50 		SCX_EQ(skel->data->uei.exit_code, tc);
51 		sprintf(buf, "%d", tc);
52 		SCX_ASSERT(!strcmp(skel->data->uei.msg, buf));
53 		bpf_link__destroy(link);
54 		exit__destroy(skel);
55 	}
56 
57 	return SCX_TEST_PASS;
58 }
59 
60 struct scx_test exit_test = {
61 	.name = "exit",
62 	.description = "Verify we can cleanly exit a scheduler in multiple places",
63 	.run = run,
64 };
65 REGISTER_SCX_TEST(&exit_test)
66