tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2025 Andrea Righi <arighi@nvidia.com>
4 */
5#include <bpf/bpf.h>
6#include <scx/common.h>
7#include <sys/wait.h>
8#include <unistd.h>
9#include "allowed_cpus.bpf.skel.h"
10#include "scx_test.h"
11
12static enum scx_test_status setup(void **ctx)
13{
14 struct allowed_cpus *skel;
15
16 skel = allowed_cpus__open();
17 SCX_FAIL_IF(!skel, "Failed to open");
18 SCX_ENUM_INIT(skel);
19 SCX_FAIL_IF(allowed_cpus__load(skel), "Failed to load skel");
20
21 *ctx = skel;
22
23 return SCX_TEST_PASS;
24}
25
26static int test_select_cpu_from_user(const struct allowed_cpus *skel)
27{
28 int fd, ret;
29 __u64 args[1];
30
31 LIBBPF_OPTS(bpf_test_run_opts, attr,
32 .ctx_in = args,
33 .ctx_size_in = sizeof(args),
34 );
35
36 args[0] = getpid();
37 fd = bpf_program__fd(skel->progs.select_cpu_from_user);
38 if (fd < 0)
39 return fd;
40
41 ret = bpf_prog_test_run_opts(fd, &attr);
42 if (ret < 0)
43 return ret;
44
45 fprintf(stderr, "%s: CPU %d\n", __func__, attr.retval);
46
47 return 0;
48}
49
50static enum scx_test_status run(void *ctx)
51{
52 struct allowed_cpus *skel = ctx;
53 struct bpf_link *link;
54
55 link = bpf_map__attach_struct_ops(skel->maps.allowed_cpus_ops);
56 SCX_FAIL_IF(!link, "Failed to attach scheduler");
57
58 /* Pick an idle CPU from user-space */
59 SCX_FAIL_IF(test_select_cpu_from_user(skel), "Failed to pick idle CPU");
60
61 /* Just sleeping is fine, plenty of scheduling events happening */
62 sleep(1);
63
64 SCX_EQ(skel->data->uei.kind, EXIT_KIND(SCX_EXIT_NONE));
65 bpf_link__destroy(link);
66
67 return SCX_TEST_PASS;
68}
69
70static void cleanup(void *ctx)
71{
72 struct allowed_cpus *skel = ctx;
73
74 allowed_cpus__destroy(skel);
75}
76
77struct scx_test allowed_cpus = {
78 .name = "allowed_cpus",
79 .description = "Verify scx_bpf_select_cpu_and()",
80 .setup = setup,
81 .run = run,
82 .cleanup = cleanup,
83};
84REGISTER_SCX_TEST(&allowed_cpus)