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Date:   Sat, 4 Jun 2022 12:31:52 -0700
From:   Yury Norov <yury.norov@gmail.com>
To:     Sander Vanheule <sander@svanheule.net>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Valentin Schneider <vschneid@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Marco Elver <elver@google.com>, linux-kernel@vger.kernel.org,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Subject: Re: [PATCH v2 1/4] lib/test: Introduce cpumask KUnit test suite
Message-ID: <YpuzKLQdToIwBrSm@yury-laptop>
References: <cover.1654362935.git.sander@svanheule.net>
 <5a55f41812dc18fccf66f8130682ff8e669e0c80.1654362935.git.sander@svanheule.net>
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On Sat, Jun 04, 2022 at 07:15:56PM +0200, Sander Vanheule wrote:
> Add a basic suite of tests for cpumask, providing some tests for empty
> and completely filled cpumasks.
> 
> Signed-off-by: Sander Vanheule <sander@svanheule.net>

The test must go after fix, so that it's doesn't cause regressions
while bisecting.

> ---
>  lib/Kconfig.debug  |   9 ++++
>  lib/Makefile       |   1 +
>  lib/test_cpumask.c | 115 +++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 125 insertions(+)
>  create mode 100644 lib/test_cpumask.c

[..]

> +#define FOR_EACH_ITER_EQ(_test, _iter, _expect, _loop)		\
> +	do {							\
> +		(_iter) = 0;					\
> +		_loop						\
> +			(_iter)++;				\
> +		KUNIT_EXPECT_EQ((_test), (_expect), (_iter));	\
> +	} while (0)

This one is harder to use than it should be. Maybe like this? (not tested,
just an idea)

#define TEST_FOR_EACH_CPU_EQ(test, mask)                                \
	do {							        \
                cpumask_t *m = (mask);                                  \
                int iter = 0, cpu;                                      \
		for_each_cpu(cpu, m)		                        \
			iter++;			        	        \
		KUNIT_EXPECT_EQ((test), cpumask_weight(m), iter);	\
	} while (0)

static void test_cpumask_iterators(struct kunit *test)
{
        TEST_FOR_EACH_CPU(test, &mask_empty);
        ...
}
 
Similarly for NOT and WRAP.

Thanks,
Yury

> +static cpumask_t mask_empty;
> +static cpumask_t mask_all;
> +
> +static void test_cpumask_weight(struct kunit *test)
> +{
> +	KUNIT_EXPECT_TRUE(test, cpumask_empty(&mask_empty));
> +	KUNIT_EXPECT_TRUE(test, cpumask_full(cpu_possible_mask));
> +	KUNIT_EXPECT_TRUE(test, cpumask_full(&mask_all));
> +
> +	KUNIT_EXPECT_EQ(test, 0, cpumask_weight(&mask_empty));
> +	KUNIT_EXPECT_EQ(test, nr_cpu_ids, cpumask_weight(cpu_possible_mask));
> +	KUNIT_EXPECT_EQ(test, nr_cpumask_bits, cpumask_weight(&mask_all));
> +}
> +
> +static void test_cpumask_first(struct kunit *test)
> +{
> +	KUNIT_EXPECT_LE(test, nr_cpu_ids, cpumask_first(&mask_empty));
> +	KUNIT_EXPECT_EQ(test, 0, cpumask_first(cpu_possible_mask));
> +
> +	KUNIT_EXPECT_EQ(test, 0, cpumask_first_zero(&mask_empty));
> +	KUNIT_EXPECT_LE(test, nr_cpu_ids, cpumask_first_zero(cpu_possible_mask));
> +}
> +
> +static void test_cpumask_last(struct kunit *test)
> +{
> +	KUNIT_EXPECT_LE(test, nr_cpumask_bits, cpumask_last(&mask_empty));
> +	KUNIT_EXPECT_EQ(test, nr_cpumask_bits - 1, cpumask_last(cpu_possible_mask));
> +}
> +
> +static void test_cpumask_next(struct kunit *test)
> +{
> +	KUNIT_EXPECT_EQ(test, 0, cpumask_next_zero(-1, &mask_empty));
> +	KUNIT_EXPECT_LE(test, nr_cpu_ids, cpumask_next_zero(-1, cpu_possible_mask));
> +
> +	KUNIT_EXPECT_LE(test, nr_cpu_ids, cpumask_next(-1, &mask_empty));
> +	KUNIT_EXPECT_EQ(test, 0, cpumask_next(-1, cpu_possible_mask));
> +}
> +
> +static void test_cpumask_iterators(struct kunit *test)
> +{
> +	unsigned int iterations;
> +	int cpu;
> +
> +	FOR_EACH_ITER_EQ(test, iterations, cpumask_weight(&mask_empty),
> +			for_each_cpu(cpu, &mask_empty));
> +	FOR_EACH_ITER_EQ(test, iterations, nr_cpu_ids - cpumask_weight(&mask_empty),
> +			for_each_cpu_not(cpu, &mask_empty));
> +	FOR_EACH_ITER_EQ(test, iterations, cpumask_weight(&mask_empty),
> +			for_each_cpu_wrap(cpu, &mask_empty, nr_cpu_ids / 2));
> +
> +	FOR_EACH_ITER_EQ(test, iterations, cpumask_weight(cpu_possible_mask),
> +			for_each_cpu(cpu, cpu_possible_mask));
> +	FOR_EACH_ITER_EQ(test, iterations, nr_cpu_ids - cpumask_weight(cpu_possible_mask),
> +			for_each_cpu_not(cpu, cpu_possible_mask));
> +	FOR_EACH_ITER_EQ(test, iterations, cpumask_weight(cpu_possible_mask),
> +			for_each_cpu_wrap(cpu, cpu_possible_mask, nr_cpu_ids / 2));
> +}
> +
> +static void test_cpumask_iterators_builtin(struct kunit *test)
> +{
> +	unsigned int iterations;
> +	int cpu;
> +
> +	FOR_EACH_ITER_EQ(test, iterations, nr_cpu_ids,
> +		for_each_possible_cpu(cpu));
> +	FOR_EACH_ITER_EQ(test, iterations, cpumask_weight(cpu_online_mask),
> +		for_each_online_cpu(cpu));
> +	FOR_EACH_ITER_EQ(test, iterations, cpumask_weight(cpu_present_mask),
> +		for_each_present_cpu(cpu));
> +}
> +
> +static int test_cpumask_init(struct kunit *test)
> +{
> +	cpumask_clear(&mask_empty);
> +	cpumask_setall(&mask_all);
> +
> +	return 0;
> +}
> +
> +static struct kunit_case test_cpumask_cases[] = {
> +	KUNIT_CASE(test_cpumask_weight),
> +	KUNIT_CASE(test_cpumask_first),
> +	KUNIT_CASE(test_cpumask_last),
> +	KUNIT_CASE(test_cpumask_next),
> +	KUNIT_CASE(test_cpumask_iterators),
> +	KUNIT_CASE(test_cpumask_iterators_builtin),
> +	{}
> +};
> +
> +static struct kunit_suite test_cpumask_suite = {
> +	.name = "cpumask",
> +	.init = test_cpumask_init,
> +	.test_cases = test_cpumask_cases,
> +};
> +kunit_test_suite(test_cpumask_suite);
> +
> +MODULE_LICENSE("GPL");
> -- 
> 2.36.1