xref: /linux/tools/testing/selftests/sched_ext/enq_select_cpu.c (revision feacb1774bd5eac6382990d0f6d1378dc01dd78f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2023 Meta Platforms, Inc. and affiliates.
4  * Copyright (c) 2023 David Vernet <dvernet@meta.com>
5  * Copyright (c) 2023 Tejun Heo <tj@kernel.org>
6  */
7 #include <bpf/bpf.h>
8 #include <scx/common.h>
9 #include <sys/wait.h>
10 #include <unistd.h>
11 #include "enq_select_cpu.bpf.skel.h"
12 #include "scx_test.h"
13 
14 static enum scx_test_status setup(void **ctx)
15 {
16 	struct enq_select_cpu *skel;
17 
18 	skel = enq_select_cpu__open();
19 	SCX_FAIL_IF(!skel, "Failed to open");
20 	SCX_ENUM_INIT(skel);
21 	SCX_FAIL_IF(enq_select_cpu__load(skel), "Failed to load skel");
22 
23 	*ctx = skel;
24 
25 	return SCX_TEST_PASS;
26 }
27 
28 static int test_select_cpu_from_user(const struct enq_select_cpu *skel)
29 {
30 	int fd, ret;
31 	__u64 args[1];
32 
33 	LIBBPF_OPTS(bpf_test_run_opts, attr,
34 		.ctx_in = args,
35 		.ctx_size_in = sizeof(args),
36 	);
37 
38 	args[0] = getpid();
39 	fd = bpf_program__fd(skel->progs.select_cpu_from_user);
40 	if (fd < 0)
41 		return fd;
42 
43 	ret = bpf_prog_test_run_opts(fd, &attr);
44 	if (ret < 0)
45 		return ret;
46 
47 	fprintf(stderr, "%s: CPU %d\n", __func__, attr.retval);
48 
49 	return 0;
50 }
51 
52 static enum scx_test_status run(void *ctx)
53 {
54 	struct enq_select_cpu *skel = ctx;
55 	struct bpf_link *link;
56 
57 	link = bpf_map__attach_struct_ops(skel->maps.enq_select_cpu_ops);
58 	if (!link) {
59 		SCX_ERR("Failed to attach scheduler");
60 		return SCX_TEST_FAIL;
61 	}
62 
63 	/* Pick an idle CPU from user-space */
64 	SCX_FAIL_IF(test_select_cpu_from_user(skel), "Failed to pick idle CPU");
65 
66 	sleep(1);
67 
68 	SCX_EQ(skel->data->uei.kind, EXIT_KIND(SCX_EXIT_NONE));
69 	bpf_link__destroy(link);
70 
71 	return SCX_TEST_PASS;
72 }
73 
74 static void cleanup(void *ctx)
75 {
76 	struct enq_select_cpu *skel = ctx;
77 
78 	enq_select_cpu__destroy(skel);
79 }
80 
81 struct scx_test enq_select_cpu = {
82 	.name = "enq_select_cpu",
83 	.description = "Verify scx_bpf_select_cpu_dfl() from multiple contexts",
84 	.setup = setup,
85 	.run = run,
86 	.cleanup = cleanup,
87 };
88 REGISTER_SCX_TEST(&enq_select_cpu)
89