Commit d19e9fa6 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

lib: Add trivial kunit test for ratelimit 

Add a simple single-threaded smoke test for lib/ratelimit.c

To run on x86:

	make ARCH=x86_64 mrproper
	./tools/testing/kunit/kunit.py run --arch x86_64 --kconfig_add CONFIG_RATELIMIT_KUNIT_TEST=y --kconfig_add CONFIG_SMP=y lib_ratelimit

This will fail on old ___ratelimit(), and subsequent patches provide
the fixes that are required.

[ paulmck:  Apply timeout and kunit feedback from Petr Mladek. ]

Link: https://lore.kernel.org/all/fbe93a52-365e-47fe-93a4-44a44547d601@paulmck-laptop/
Link: https://lore.kernel.org/all/20250423115409.3425-1-spasswolf@web.de/


Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jon Pan-Doh <pandoh@google.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Karolina Stolarek <karolina.stolarek@oracle.com>
parent 19272b37

lib/Kconfig.debug

+11 −0
Original line number Diff line number Diff line
@@ -3225,6 +3225,17 @@ config TEST_OBJPOOL 


	  If unsure, say N.



config RATELIMIT_KUNIT_TEST

	tristate "KUnit Test for correctness and stress of ratelimit" if !KUNIT_ALL_TESTS

	depends on KUNIT

	default KUNIT_ALL_TESTS

	help

	  This builds the "test_ratelimit" module that should be used

	  for correctness verification and concurrent testings of rate

	  limiting.



	  If unsure, say N.



config INT_POW_KUNIT_TEST

	tristate "Integer exponentiation (int_pow) test" if !KUNIT_ALL_TESTS

	depends on KUNIT

lib/tests/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -46,5 +46,6 @@ obj-$(CONFIG_STRING_KUNIT_TEST) += string_kunit.o 
obj-$(CONFIG_STRING_HELPERS_KUNIT_TEST) += string_helpers_kunit.o

obj-$(CONFIG_USERCOPY_KUNIT_TEST) += usercopy_kunit.o

obj-$(CONFIG_UTIL_MACROS_KUNIT) += util_macros_kunit.o

obj-$(CONFIG_RATELIMIT_KUNIT_TEST) += test_ratelimit.o



obj-$(CONFIG_TEST_RUNTIME_MODULE)		+= module/

lib/tests/test_ratelimit.c

0 → 100644
+79 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only



#include <kunit/test.h>



#include <linux/ratelimit.h>

#include <linux/module.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 - 40);

	test_ratelimited(test, false);



	schedule_timeout_idle(50);

	test_ratelimited(test, true);



	schedule_timeout_idle(2 * TESTRL_INTERVAL);

	test_ratelimited(test, true);

	test_ratelimited(test, true);



	schedule_timeout_idle(TESTRL_INTERVAL - 40);

	test_ratelimited(test, true);

	schedule_timeout_idle(50);

	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 kunit_case sort_test_cases[] = {

	KUNIT_CASE_SLOW(test_ratelimit_smoke),

	{}

};



static struct kunit_suite ratelimit_test_suite = {

	.name = "lib_ratelimit",

	.test_cases = sort_test_cases,

};



kunit_test_suites(&ratelimit_test_suite);



MODULE_DESCRIPTION("___ratelimit() KUnit test suite");

MODULE_LICENSE("GPL");