xref: /linux/tools/testing/selftests/sched_ext/select_cpu_dispatch.c (revision 0c436dfe5c25d0931b164b944165259f95e5281f)
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_dispatch.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_dispatch *skel;
19 
20 	skel = select_cpu_dispatch__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_dispatch *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_dispatch_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 	bpf_link__destroy(link);
51 
52 	return SCX_TEST_PASS;
53 }
54 
55 static void cleanup(void *ctx)
56 {
57 	struct select_cpu_dispatch *skel = ctx;
58 
59 	select_cpu_dispatch__destroy(skel);
60 }
61 
62 struct scx_test select_cpu_dispatch = {
63 	.name = "select_cpu_dispatch",
64 	.description = "Test direct dispatching to built-in DSQs from "
65 		       "ops.select_cpu()",
66 	.setup = setup,
67 	.run = run,
68 	.cleanup = cleanup,
69 };
70 REGISTER_SCX_TEST(&select_cpu_dispatch)
71