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Diffstat (limited to 'lib/tests/test_ratelimit.c')
| -rw-r--r-- | lib/tests/test_ratelimit.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/lib/tests/test_ratelimit.c b/lib/tests/test_ratelimit.c new file mode 100644 index 000000000000..bfaeca49304a --- /dev/null +++ b/lib/tests/test_ratelimit.c @@ -0,0 +1,144 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <kunit/test.h> + +#include <linux/ratelimit.h> +#include <linux/module.h> +#include <linux/kthread.h> +#include <linux/cpumask.h> + +/* a simple boot-time regression test */ + +#define TESTRL_INTERVAL (5 * HZ) +static DEFINE_RATELIMIT_STATE(testrl, TESTRL_INTERVAL, 3); + +#define test_ratelimited(test, expected) \ + KUNIT_ASSERT_EQ(test, ___ratelimit(&testrl, "test_ratelimit_smoke"), (expected)) + +static void test_ratelimit_smoke(struct kunit *test) +{ + // Check settings. + KUNIT_ASSERT_GE(test, TESTRL_INTERVAL, 100); + + // Test normal operation. + test_ratelimited(test, true); + test_ratelimited(test, true); + test_ratelimited(test, true); + test_ratelimited(test, false); + + schedule_timeout_idle(TESTRL_INTERVAL / 2); + test_ratelimited(test, false); + + schedule_timeout_idle(TESTRL_INTERVAL * 3 / 4); + test_ratelimited(test, true); + + schedule_timeout_idle(2 * TESTRL_INTERVAL); + test_ratelimited(test, true); + test_ratelimited(test, true); + + schedule_timeout_idle(TESTRL_INTERVAL / 2 ); + test_ratelimited(test, true); + schedule_timeout_idle(TESTRL_INTERVAL * 3 / 4); + test_ratelimited(test, true); + test_ratelimited(test, true); + test_ratelimited(test, true); + test_ratelimited(test, false); + + // Test disabling. + testrl.burst = 0; + test_ratelimited(test, false); + testrl.burst = 2; + testrl.interval = 0; + test_ratelimited(test, true); + test_ratelimited(test, true); + test_ratelimited(test, true); + test_ratelimited(test, true); + test_ratelimited(test, true); + test_ratelimited(test, true); + test_ratelimited(test, true); + + // Testing re-enabling. + testrl.interval = TESTRL_INTERVAL; + test_ratelimited(test, true); + test_ratelimited(test, true); + test_ratelimited(test, false); + test_ratelimited(test, false); +} + +static struct ratelimit_state stressrl = RATELIMIT_STATE_INIT_FLAGS("stressrl", HZ / 10, 3, + RATELIMIT_MSG_ON_RELEASE); + +static int doneflag; +static const int stress_duration = 2 * HZ; + +struct stress_kthread { + unsigned long nattempts; + unsigned long nunlimited; + unsigned long nlimited; + unsigned long nmissed; + struct task_struct *tp; +}; + +static int test_ratelimit_stress_child(void *arg) +{ + struct stress_kthread *sktp = arg; + + set_user_nice(current, MAX_NICE); + WARN_ON_ONCE(!sktp->tp); + + while (!READ_ONCE(doneflag)) { + sktp->nattempts++; + if (___ratelimit(&stressrl, __func__)) + sktp->nunlimited++; + else + sktp->nlimited++; + cond_resched(); + } + + sktp->nmissed = ratelimit_state_reset_miss(&stressrl); + return 0; +} + +static void test_ratelimit_stress(struct kunit *test) +{ + int i; + const int n_stress_kthread = cpumask_weight(cpu_online_mask); + struct stress_kthread skt = { 0 }; + struct stress_kthread *sktp = kcalloc(n_stress_kthread, sizeof(*sktp), GFP_KERNEL); + + KUNIT_EXPECT_NOT_NULL_MSG(test, sktp, "Memory allocation failure"); + for (i = 0; i < n_stress_kthread; i++) { + sktp[i].tp = kthread_run(test_ratelimit_stress_child, &sktp[i], "%s/%i", + "test_ratelimit_stress_child", i); + KUNIT_EXPECT_NOT_NULL_MSG(test, sktp, "kthread creation failure"); + pr_alert("Spawned test_ratelimit_stress_child %d\n", i); + } + schedule_timeout_idle(stress_duration); + WRITE_ONCE(doneflag, 1); + for (i = 0; i < n_stress_kthread; i++) { + kthread_stop(sktp[i].tp); + skt.nattempts += sktp[i].nattempts; + skt.nunlimited += sktp[i].nunlimited; + skt.nlimited += sktp[i].nlimited; + skt.nmissed += sktp[i].nmissed; + } + KUNIT_ASSERT_EQ_MSG(test, skt.nunlimited + skt.nlimited, skt.nattempts, + "Outcomes not equal to attempts"); + KUNIT_ASSERT_EQ_MSG(test, skt.nlimited, skt.nmissed, "Misses not equal to limits"); +} + +static struct kunit_case ratelimit_test_cases[] = { + KUNIT_CASE_SLOW(test_ratelimit_smoke), + KUNIT_CASE_SLOW(test_ratelimit_stress), + {} +}; + +static struct kunit_suite ratelimit_test_suite = { + .name = "lib_ratelimit", + .test_cases = ratelimit_test_cases, +}; + +kunit_test_suites(&ratelimit_test_suite); + +MODULE_DESCRIPTION("___ratelimit() KUnit test suite"); +MODULE_LICENSE("GPL"); |