xref: /linux/tools/testing/selftests/sched_ext/allowed_cpus.c (revision feacb1774bd5eac6382990d0f6d1378dc01dd78f)
101d541baSAndrea Righi // SPDX-License-Identifier: GPL-2.0
201d541baSAndrea Righi /*
301d541baSAndrea Righi  * Copyright (c) 2025 Andrea Righi <arighi@nvidia.com>
401d541baSAndrea Righi  */
501d541baSAndrea Righi #include <bpf/bpf.h>
601d541baSAndrea Righi #include <scx/common.h>
701d541baSAndrea Righi #include <sys/wait.h>
801d541baSAndrea Righi #include <unistd.h>
901d541baSAndrea Righi #include "allowed_cpus.bpf.skel.h"
1001d541baSAndrea Righi #include "scx_test.h"
1101d541baSAndrea Righi 
1201d541baSAndrea Righi static enum scx_test_status setup(void **ctx)
1301d541baSAndrea Righi {
1401d541baSAndrea Righi 	struct allowed_cpus *skel;
1501d541baSAndrea Righi 
1601d541baSAndrea Righi 	skel = allowed_cpus__open();
1701d541baSAndrea Righi 	SCX_FAIL_IF(!skel, "Failed to open");
1801d541baSAndrea Righi 	SCX_ENUM_INIT(skel);
1901d541baSAndrea Righi 	SCX_FAIL_IF(allowed_cpus__load(skel), "Failed to load skel");
2001d541baSAndrea Righi 
2101d541baSAndrea Righi 	*ctx = skel;
2201d541baSAndrea Righi 
2301d541baSAndrea Righi 	return SCX_TEST_PASS;
2401d541baSAndrea Righi }
2501d541baSAndrea Righi 
26*e764295aSAndrea Righi static int test_select_cpu_from_user(const struct allowed_cpus *skel)
27*e764295aSAndrea Righi {
28*e764295aSAndrea Righi 	int fd, ret;
29*e764295aSAndrea Righi 	__u64 args[1];
30*e764295aSAndrea Righi 
31*e764295aSAndrea Righi 	LIBBPF_OPTS(bpf_test_run_opts, attr,
32*e764295aSAndrea Righi 		.ctx_in = args,
33*e764295aSAndrea Righi 		.ctx_size_in = sizeof(args),
34*e764295aSAndrea Righi 	);
35*e764295aSAndrea Righi 
36*e764295aSAndrea Righi 	args[0] = getpid();
37*e764295aSAndrea Righi 	fd = bpf_program__fd(skel->progs.select_cpu_from_user);
38*e764295aSAndrea Righi 	if (fd < 0)
39*e764295aSAndrea Righi 		return fd;
40*e764295aSAndrea Righi 
41*e764295aSAndrea Righi 	ret = bpf_prog_test_run_opts(fd, &attr);
42*e764295aSAndrea Righi 	if (ret < 0)
43*e764295aSAndrea Righi 		return ret;
44*e764295aSAndrea Righi 
45*e764295aSAndrea Righi 	fprintf(stderr, "%s: CPU %d\n", __func__, attr.retval);
46*e764295aSAndrea Righi 
47*e764295aSAndrea Righi 	return 0;
48*e764295aSAndrea Righi }
49*e764295aSAndrea Righi 
5001d541baSAndrea Righi static enum scx_test_status run(void *ctx)
5101d541baSAndrea Righi {
5201d541baSAndrea Righi 	struct allowed_cpus *skel = ctx;
5301d541baSAndrea Righi 	struct bpf_link *link;
5401d541baSAndrea Righi 
5501d541baSAndrea Righi 	link = bpf_map__attach_struct_ops(skel->maps.allowed_cpus_ops);
5601d541baSAndrea Righi 	SCX_FAIL_IF(!link, "Failed to attach scheduler");
5701d541baSAndrea Righi 
58*e764295aSAndrea Righi 	/* Pick an idle CPU from user-space */
59*e764295aSAndrea Righi 	SCX_FAIL_IF(test_select_cpu_from_user(skel), "Failed to pick idle CPU");
60*e764295aSAndrea Righi 
6101d541baSAndrea Righi 	/* Just sleeping is fine, plenty of scheduling events happening */
6201d541baSAndrea Righi 	sleep(1);
6301d541baSAndrea Righi 
6401d541baSAndrea Righi 	SCX_EQ(skel->data->uei.kind, EXIT_KIND(SCX_EXIT_NONE));
6501d541baSAndrea Righi 	bpf_link__destroy(link);
6601d541baSAndrea Righi 
6701d541baSAndrea Righi 	return SCX_TEST_PASS;
6801d541baSAndrea Righi }
6901d541baSAndrea Righi 
7001d541baSAndrea Righi static void cleanup(void *ctx)
7101d541baSAndrea Righi {
7201d541baSAndrea Righi 	struct allowed_cpus *skel = ctx;
7301d541baSAndrea Righi 
7401d541baSAndrea Righi 	allowed_cpus__destroy(skel);
7501d541baSAndrea Righi }
7601d541baSAndrea Righi 
7701d541baSAndrea Righi struct scx_test allowed_cpus = {
7801d541baSAndrea Righi 	.name = "allowed_cpus",
7901d541baSAndrea Righi 	.description = "Verify scx_bpf_select_cpu_and()",
8001d541baSAndrea Righi 	.setup = setup,
8101d541baSAndrea Righi 	.run = run,
8201d541baSAndrea Righi 	.cleanup = cleanup,
8301d541baSAndrea Righi };
8401d541baSAndrea Righi REGISTER_SCX_TEST(&allowed_cpus)
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