exit.c

 1/* SPDX-License-Identifier: GPL-2.0 */
 2/*
 3 * Copyright (c) 2024 Meta Platforms, Inc. and affiliates.
 4 * Copyright (c) 2024 David Vernet <dvernet@meta.com>
 5 */
 6#include <bpf/bpf.h>
 7#include <sched.h>
 8#include <scx/common.h>
 9#include <sys/wait.h>
10#include <unistd.h>
11#include "exit.bpf.skel.h"
12#include "scx_test.h"
13
14#include "exit_test.h"
15
16static enum scx_test_status run(void *ctx)
17{
18	enum exit_test_case tc;
19
20	for (tc = 0; tc < NUM_EXITS; tc++) {
21		struct exit *skel;
22		struct bpf_link *link;
23		char buf[16];
24
25		/*
26		 * On single-CPU systems, ops.select_cpu() is never
27		 * invoked, so skip this test to avoid getting stuck
28		 * indefinitely.
29		 */
30		if (tc == EXIT_SELECT_CPU && libbpf_num_possible_cpus() == 1)
31			continue;
32
33		skel = exit__open();
34		SCX_ENUM_INIT(skel);
35		skel->rodata->exit_point = tc;
36		exit__load(skel);
37		link = bpf_map__attach_struct_ops(skel->maps.exit_ops);
38		if (!link) {
39			SCX_ERR("Failed to attach scheduler");
40			exit__destroy(skel);
41			return SCX_TEST_FAIL;
42		}
43
44		/* Assumes uei.kind is written last */
45		while (skel->data->uei.kind == EXIT_KIND(SCX_EXIT_NONE))
46			sched_yield();
47
48		SCX_EQ(skel->data->uei.kind, EXIT_KIND(SCX_EXIT_UNREG_BPF));
49		SCX_EQ(skel->data->uei.exit_code, tc);
50		sprintf(buf, "%d", tc);
51		SCX_ASSERT(!strcmp(skel->data->uei.msg, buf));
52		bpf_link__destroy(link);
53		exit__destroy(skel);
54	}
55
56	return SCX_TEST_PASS;
57}
58
59struct scx_test exit_test = {
60	.name = "exit",
61	.description = "Verify we can cleanly exit a scheduler in multiple places",
62	.run = run,
63};
64REGISTER_SCX_TEST(&exit_test)