xref: /linux/tools/testing/selftests/sched_ext/select_cpu_dfl_nodispatch.c (revision 566ab427f827b0256d3e8ce0235d088e6a9c28bd)
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 "select_cpu_dfl_nodispatch.bpf.skel.h"
12 #include "scx_test.h"
13 
14 #define NUM_CHILDREN 1028
15 
16 static enum scx_test_status setup(void **ctx)
17 {
18 	struct select_cpu_dfl_nodispatch *skel;
19 
20 	skel = select_cpu_dfl_nodispatch__open_and_load();
21 	SCX_FAIL_IF(!skel, "Failed to open and load skel");
22 	*ctx = skel;
23 
24 	return SCX_TEST_PASS;
25 }
26 
27 static enum scx_test_status run(void *ctx)
28 {
29 	struct select_cpu_dfl_nodispatch *skel = ctx;
30 	struct bpf_link *link;
31 	pid_t pids[NUM_CHILDREN];
32 	int i, status;
33 
34 	link = bpf_map__attach_struct_ops(skel->maps.select_cpu_dfl_nodispatch_ops);
35 	SCX_FAIL_IF(!link, "Failed to attach scheduler");
36 
37 	for (i = 0; i < NUM_CHILDREN; i++) {
38 		pids[i] = fork();
39 		if (pids[i] == 0) {
40 			sleep(1);
41 			exit(0);
42 		}
43 	}
44 
45 	for (i = 0; i < NUM_CHILDREN; i++) {
46 		SCX_EQ(waitpid(pids[i], &status, 0), pids[i]);
47 		SCX_EQ(status, 0);
48 	}
49 
50 	SCX_ASSERT(skel->bss->saw_local);
51 
52 	bpf_link__destroy(link);
53 
54 	return SCX_TEST_PASS;
55 }
56 
57 static void cleanup(void *ctx)
58 {
59 	struct select_cpu_dfl_nodispatch *skel = ctx;
60 
61 	select_cpu_dfl_nodispatch__destroy(skel);
62 }
63 
64 struct scx_test select_cpu_dfl_nodispatch = {
65 	.name = "select_cpu_dfl_nodispatch",
66 	.description = "Verify behavior of scx_bpf_select_cpu_dfl() in "
67 		       "ops.select_cpu()",
68 	.setup = setup,
69 	.run = run,
70 	.cleanup = cleanup,
71 };
72 REGISTER_SCX_TEST(&select_cpu_dfl_nodispatch)
73