Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-only
2
3#include <kunit/test.h>
4
5#include <linux/ratelimit.h>
6#include <linux/module.h>
7#include <linux/kthread.h>
8#include <linux/cpumask.h>
9
10/* a simple boot-time regression test */
11
12#define TESTRL_INTERVAL (5 * HZ)
13static DEFINE_RATELIMIT_STATE(testrl, TESTRL_INTERVAL, 3);
14
15#define test_ratelimited(test, expected) \
16 KUNIT_ASSERT_EQ(test, ___ratelimit(&testrl, "test_ratelimit_smoke"), (expected))
17
18static void test_ratelimit_smoke(struct kunit *test)
19{
20 // Check settings.
21 KUNIT_ASSERT_GE(test, TESTRL_INTERVAL, 100);
22
23 // Test normal operation.
24 test_ratelimited(test, true);
25 test_ratelimited(test, true);
26 test_ratelimited(test, true);
27 test_ratelimited(test, false);
28
29 schedule_timeout_idle(TESTRL_INTERVAL / 2);
30 test_ratelimited(test, false);
31
32 schedule_timeout_idle(TESTRL_INTERVAL * 3 / 4);
33 test_ratelimited(test, true);
34
35 schedule_timeout_idle(2 * TESTRL_INTERVAL);
36 test_ratelimited(test, true);
37 test_ratelimited(test, true);
38
39 schedule_timeout_idle(TESTRL_INTERVAL / 2 );
40 test_ratelimited(test, true);
41 schedule_timeout_idle(TESTRL_INTERVAL * 3 / 4);
42 test_ratelimited(test, true);
43 test_ratelimited(test, true);
44 test_ratelimited(test, true);
45 test_ratelimited(test, false);
46
47 // Test disabling.
48 testrl.burst = 0;
49 test_ratelimited(test, false);
50 testrl.burst = 2;
51 testrl.interval = 0;
52 test_ratelimited(test, true);
53 test_ratelimited(test, true);
54 test_ratelimited(test, true);
55 test_ratelimited(test, true);
56 test_ratelimited(test, true);
57 test_ratelimited(test, true);
58 test_ratelimited(test, true);
59
60 // Testing re-enabling.
61 testrl.interval = TESTRL_INTERVAL;
62 test_ratelimited(test, true);
63 test_ratelimited(test, true);
64 test_ratelimited(test, false);
65 test_ratelimited(test, false);
66}
67
68static struct ratelimit_state stressrl = RATELIMIT_STATE_INIT_FLAGS("stressrl", HZ / 10, 3,
69 RATELIMIT_MSG_ON_RELEASE);
70
71static int doneflag;
72static const int stress_duration = 2 * HZ;
73
74struct stress_kthread {
75 unsigned long nattempts;
76 unsigned long nunlimited;
77 unsigned long nlimited;
78 unsigned long nmissed;
79 struct task_struct *tp;
80};
81
82static int test_ratelimit_stress_child(void *arg)
83{
84 struct stress_kthread *sktp = arg;
85
86 set_user_nice(current, MAX_NICE);
87 WARN_ON_ONCE(!sktp->tp);
88
89 while (!READ_ONCE(doneflag)) {
90 sktp->nattempts++;
91 if (___ratelimit(&stressrl, __func__))
92 sktp->nunlimited++;
93 else
94 sktp->nlimited++;
95 cond_resched();
96 }
97
98 sktp->nmissed = ratelimit_state_reset_miss(&stressrl);
99 return 0;
100}
101
102static void test_ratelimit_stress(struct kunit *test)
103{
104 int i;
105 const int n_stress_kthread = cpumask_weight(cpu_online_mask);
106 struct stress_kthread skt = { 0 };
107 struct stress_kthread *sktp = kcalloc(n_stress_kthread, sizeof(*sktp), GFP_KERNEL);
108
109 KUNIT_EXPECT_NOT_NULL_MSG(test, sktp, "Memory allocation failure");
110 for (i = 0; i < n_stress_kthread; i++) {
111 sktp[i].tp = kthread_run(test_ratelimit_stress_child, &sktp[i], "%s/%i",
112 "test_ratelimit_stress_child", i);
113 KUNIT_EXPECT_NOT_NULL_MSG(test, sktp, "kthread creation failure");
114 pr_alert("Spawned test_ratelimit_stress_child %d\n", i);
115 }
116 schedule_timeout_idle(stress_duration);
117 WRITE_ONCE(doneflag, 1);
118 for (i = 0; i < n_stress_kthread; i++) {
119 kthread_stop(sktp[i].tp);
120 skt.nattempts += sktp[i].nattempts;
121 skt.nunlimited += sktp[i].nunlimited;
122 skt.nlimited += sktp[i].nlimited;
123 skt.nmissed += sktp[i].nmissed;
124 }
125 KUNIT_ASSERT_EQ_MSG(test, skt.nunlimited + skt.nlimited, skt.nattempts,
126 "Outcomes not equal to attempts");
127 KUNIT_ASSERT_EQ_MSG(test, skt.nlimited, skt.nmissed, "Misses not equal to limits");
128}
129
130static struct kunit_case ratelimit_test_cases[] = {
131 KUNIT_CASE_SLOW(test_ratelimit_smoke),
132 KUNIT_CASE_SLOW(test_ratelimit_stress),
133 {}
134};
135
136static struct kunit_suite ratelimit_test_suite = {
137 .name = "lib_ratelimit",
138 .test_cases = ratelimit_test_cases,
139};
140
141kunit_test_suites(&ratelimit_test_suite);
142
143MODULE_DESCRIPTION("___ratelimit() KUnit test suite");
144MODULE_LICENSE("GPL");