This is a clear example of a unit test.
I tested this using:
$ tools/testing/kunit/kunit.py run --arch arm64 --make_options LLVM=1 math-prime_numbers
On success: ; [08:51:41] ============== math-prime_numbers (1 subtest) ============== ; [08:51:41] [PASSED] prime_numbers_test ; [08:51:41] =============== [PASSED] math-prime_numbers ================ ; [08:51:41] ============================================================ ; [08:51:41] Testing complete. Ran 1 tests: passed: 1
On failure: ; [08:50:19] ============== math-prime_numbers (1 subtest) ============== ; [08:50:19] # prime_numbers_test: ASSERTION FAILED at lib/math/tests/prime_numbers_kunit.c:28 ; [08:50:19] Expected slow == fast, but ; [08:50:19] slow == 0 (0x0) ; [08:50:19] fast == 1 (0x1) ; [08:50:19] is-prime(2) ; [08:50:19] [FAILED] prime_numbers_test ; [08:50:19] # module: prime_numbers_kunit ; [08:50:19] # math-prime_numbers: primes.{last=61, .sz=64, .primes[]=...x28208a20a08a28ac} = 2-3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61 ; [08:50:19] =============== [FAILED] math-prime_numbers ================ ; [08:50:19] ============================================================ ; [08:50:19] Testing complete. Ran 1 tests: failed: 1
Signed-off-by: Tamir Duberstein tamird@gmail.com --- Changes in v4: - Use `#if IS_ENABLED` to handle `CONFIG_PRIME_NUMBERS_KUNIT_TEST=m`. (Andrew Morton) - Link to v3: https://lore.kernel.org/r/20250208-prime_numbers-kunit-convert-v3-0-8ffd5816...
Changes in v3: - Remove `selftest_max` again; snuck into v2. - Restore `#include <linux/slab.h>`. - Sending v3 early because kernel test robot is sad. - Link to v2: https://lore.kernel.org/r/20250208-prime_numbers-kunit-convert-v2-0-86311944...
Changes in v2: - Keep all the details hidden in prime_numbers.c; expose `with_primes` for debug logging in the test. (David Gow) - Link to v1: https://lore.kernel.org/r/20250207-prime_numbers-kunit-convert-v1-0-6067f2b7...
--- Tamir Duberstein (2): lib/math: Hook up tests/Makefile lib/prime_numbers: convert self-test to KUnit
lib/Kconfig.debug | 14 +++++ lib/math/Makefile | 4 +- lib/math/prime_numbers.c | 76 ++++------------------------ lib/math/prime_numbers_private.h | 17 +++++++ lib/math/tests/Makefile | 1 + lib/math/tests/prime_numbers_kunit.c | 59 +++++++++++++++++++++ tools/testing/selftests/lib/config | 1 - tools/testing/selftests/lib/prime_numbers.sh | 4 -- 8 files changed, 102 insertions(+), 74 deletions(-) --- base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b change-id: 20250207-prime_numbers-kunit-convert-71c9b3c1d1d4
Best regards,
This Makefile has been dead code since it was added in commit 7fcc9b53216c ("lib/math: Add int_pow test suite"); the tests worked because of the duplicated rules in the parent directory's Makefile. Wire up tests/Makefile and remove the duplication.
Fixes: 7fcc9b53216c ("lib/math: Add int_pow test suite") Reviewed-by: David Gow davidgow@google.com Signed-off-by: Tamir Duberstein tamird@gmail.com --- lib/math/Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/lib/math/Makefile b/lib/math/Makefile index 853f023ae537..d390da9a59fe 100644 --- a/lib/math/Makefile +++ b/lib/math/Makefile @@ -5,8 +5,8 @@ obj-$(CONFIG_CORDIC) += cordic.o obj-$(CONFIG_PRIME_NUMBERS) += prime_numbers.o obj-$(CONFIG_RATIONAL) += rational.o
-obj-$(CONFIG_INT_POW_TEST) += tests/int_pow_kunit.o obj-$(CONFIG_TEST_DIV64) += test_div64.o obj-$(CONFIG_TEST_MULDIV64) += test_mul_u64_u64_div_u64.o obj-$(CONFIG_RATIONAL_KUNIT_TEST) += rational-test.o -obj-$(CONFIG_INT_SQRT_KUNIT_TEST) += tests/int_sqrt_kunit.o \ No newline at end of file + +obj-y += tests/
Extract a private header and convert the prime_numbers self-test to a KUnit test. I considered parameterizing the test using `KUNIT_CASE_PARAM` but didn't see how it was possible since the test logic is entangled with the test parameter generation logic.
Signed-off-by: Tamir Duberstein tamird@gmail.com --- lib/Kconfig.debug | 14 +++++ lib/math/prime_numbers.c | 76 ++++------------------------ lib/math/prime_numbers_private.h | 17 +++++++ lib/math/tests/Makefile | 1 + lib/math/tests/prime_numbers_kunit.c | 59 +++++++++++++++++++++ tools/testing/selftests/lib/config | 1 - tools/testing/selftests/lib/prime_numbers.sh | 4 -- 7 files changed, 100 insertions(+), 72 deletions(-)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 1af972a92d06..616beaca4a2b 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -3197,6 +3197,20 @@ config INT_SQRT_KUNIT_TEST
If unsure, say N
+config PRIME_NUMBERS_KUNIT_TEST + tristate "Prime number generator test" if !KUNIT_ALL_TESTS + depends on KUNIT + select PRIME_NUMBERS + default KUNIT_ALL_TESTS + help + This option enables the KUnit test suite for the {is,next}_prime_number + functions. + + Enabling this option will include tests that compare the prime number + generator functions against a brute force implementation. + + If unsure, say N + endif # RUNTIME_TESTING_MENU
config ARCH_USE_MEMTEST diff --git a/lib/math/prime_numbers.c b/lib/math/prime_numbers.c index 9a17ee9af93a..1d20d068dacf 100644 --- a/lib/math/prime_numbers.c +++ b/lib/math/prime_numbers.c @@ -1,16 +1,11 @@ // SPDX-License-Identifier: GPL-2.0-only -#define pr_fmt(fmt) "prime numbers: " fmt
#include <linux/module.h> #include <linux/mutex.h> #include <linux/prime_numbers.h> #include <linux/slab.h>
-struct primes { - struct rcu_head rcu; - unsigned long last, sz; - unsigned long primes[]; -}; +#include "prime_numbers_private.h"
#if BITS_PER_LONG == 64 static const struct primes small_primes = { @@ -62,9 +57,13 @@ static const struct primes small_primes = { static DEFINE_MUTEX(lock); static const struct primes __rcu *primes = RCU_INITIALIZER(&small_primes);
-static unsigned long selftest_max; +#if IS_ENABLED(CONFIG_PRIME_NUMBERS_KUNIT_TEST) +EXPORT_SYMBOL(slow_is_prime_number);
-static bool slow_is_prime_number(unsigned long x) +#else +static +#endif +bool slow_is_prime_number(unsigned long x) { unsigned long y = int_sqrt(x);
@@ -239,65 +238,11 @@ bool is_prime_number(unsigned long x) } EXPORT_SYMBOL(is_prime_number);
-static void dump_primes(void) +void with_primes(void *ctx, primes_fn fn) { - const struct primes *p; - char *buf; - - buf = kmalloc(PAGE_SIZE, GFP_KERNEL); - rcu_read_lock(); - p = rcu_dereference(primes); - - if (buf) - bitmap_print_to_pagebuf(true, buf, p->primes, p->sz); - pr_info("primes.{last=%lu, .sz=%lu, .primes[]=...x%lx} = %s\n", - p->last, p->sz, p->primes[BITS_TO_LONGS(p->sz) - 1], buf); - + fn(ctx, rcu_dereference(primes)); rcu_read_unlock(); - - kfree(buf); -} - -static int selftest(unsigned long max) -{ - unsigned long x, last; - - if (!max) - return 0; - - for (last = 0, x = 2; x < max; x++) { - bool slow = slow_is_prime_number(x); - bool fast = is_prime_number(x); - - if (slow != fast) { - pr_err("inconsistent result for is-prime(%lu): slow=%s, fast=%s!\n", - x, slow ? "yes" : "no", fast ? "yes" : "no"); - goto err; - } - - if (!slow) - continue; - - if (next_prime_number(last) != x) { - pr_err("incorrect result for next-prime(%lu): expected %lu, got %lu\n", - last, x, next_prime_number(last)); - goto err; - } - last = x; - } - - pr_info("%s(%lu) passed, last prime was %lu\n", __func__, x, last); - return 0; - -err: - dump_primes(); - return -EINVAL; -} - -static int __init primes_init(void) -{ - return selftest(selftest_max); }
static void __exit primes_exit(void) @@ -305,11 +250,8 @@ static void __exit primes_exit(void) free_primes(); }
-module_init(primes_init); module_exit(primes_exit);
-module_param_named(selftest, selftest_max, ulong, 0400); - MODULE_AUTHOR("Intel Corporation"); MODULE_DESCRIPTION("Prime number library"); MODULE_LICENSE("GPL"); diff --git a/lib/math/prime_numbers_private.h b/lib/math/prime_numbers_private.h new file mode 100644 index 000000000000..4d0504459490 --- /dev/null +++ b/lib/math/prime_numbers_private.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include <linux/types.h> + +struct primes { + struct rcu_head rcu; + unsigned long last, sz; + unsigned long primes[]; +}; + +#if IS_ENABLED(CONFIG_PRIME_NUMBERS_KUNIT_TEST) +bool slow_is_prime_number(unsigned long x); +#endif +typedef void (*primes_fn)(void *, const struct primes *); + +// Calls the callback under RCU lock. The callback must not retain the primes pointer. +void with_primes(void *ctx, primes_fn fn); diff --git a/lib/math/tests/Makefile b/lib/math/tests/Makefile index e1a79f093b2d..da21a592c75a 100644 --- a/lib/math/tests/Makefile +++ b/lib/math/tests/Makefile @@ -2,3 +2,4 @@
obj-$(CONFIG_INT_POW_TEST) += int_pow_kunit.o obj-$(CONFIG_INT_SQRT_KUNIT_TEST) += int_sqrt_kunit.o +obj-$(CONFIG_PRIME_NUMBERS_KUNIT_TEST) += prime_numbers_kunit.o diff --git a/lib/math/tests/prime_numbers_kunit.c b/lib/math/tests/prime_numbers_kunit.c new file mode 100644 index 000000000000..2f1643208c66 --- /dev/null +++ b/lib/math/tests/prime_numbers_kunit.c @@ -0,0 +1,59 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <kunit/test.h> +#include <linux/module.h> +#include <linux/prime_numbers.h> + +#include "../prime_numbers_private.h" + +static void dump_primes(void *ctx, const struct primes *p) +{ + static char buf[PAGE_SIZE]; + struct kunit_suite *suite = ctx; + + bitmap_print_to_pagebuf(true, buf, p->primes, p->sz); + kunit_info(suite, "primes.{last=%lu, .sz=%lu, .primes[]=...x%lx} = %s", + p->last, p->sz, p->primes[BITS_TO_LONGS(p->sz) - 1], buf); +} + +static void prime_numbers_test(struct kunit *test) +{ + const unsigned long max = 65536; + unsigned long x, last, next; + + for (last = 0, x = 2; x < max; x++) { + const bool slow = slow_is_prime_number(x); + const bool fast = is_prime_number(x); + + KUNIT_ASSERT_EQ_MSG(test, slow, fast, "is-prime(%lu)", x); + + if (!slow) + continue; + + next = next_prime_number(last); + KUNIT_ASSERT_EQ_MSG(test, next, x, "next-prime(%lu)", last); + last = next; + } +} + +static void kunit_suite_exit(struct kunit_suite *suite) +{ + with_primes(suite, dump_primes); +} + +static struct kunit_case prime_numbers_cases[] = { + KUNIT_CASE(prime_numbers_test), + {}, +}; + +static struct kunit_suite prime_numbers_suite = { + .name = "math-prime_numbers", + .suite_exit = kunit_suite_exit, + .test_cases = prime_numbers_cases, +}; + +kunit_test_suite(prime_numbers_suite); + +MODULE_AUTHOR("Intel Corporation"); +MODULE_DESCRIPTION("Prime number library"); +MODULE_LICENSE("GPL"); diff --git a/tools/testing/selftests/lib/config b/tools/testing/selftests/lib/config index dc15aba8d0a3..306a3d4dca98 100644 --- a/tools/testing/selftests/lib/config +++ b/tools/testing/selftests/lib/config @@ -1,5 +1,4 @@ CONFIG_TEST_PRINTF=m CONFIG_TEST_SCANF=m CONFIG_TEST_BITMAP=m -CONFIG_PRIME_NUMBERS=m CONFIG_TEST_BITOPS=m diff --git a/tools/testing/selftests/lib/prime_numbers.sh b/tools/testing/selftests/lib/prime_numbers.sh deleted file mode 100755 index 370b79a9cb2e..000000000000 --- a/tools/testing/selftests/lib/prime_numbers.sh +++ /dev/null @@ -1,4 +0,0 @@ -#!/bin/sh -# SPDX-License-Identifier: GPL-2.0 -# Checks fast/slow prime_number generation for inconsistencies -$(dirname $0)/../kselftest/module.sh "prime numbers" prime_numbers selftest=65536
linux-kselftest-mirror@lists.linaro.org
-
Tamir Duberstein