cpumask: Fix invalid uniprocessor assumptions

Add a basic suite of tests for cpumask, providing some tests for empty and completely filled cpumasks.

Signed-off-by Sander Vanheule <[email protected]>

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

lib/test_cpumask.c new file +97 -0

+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");

Signature · 1 line

2.36.1

Quoted 4 lines · Sander Vanheule

Add a basic suite of tests for cpumask, providing some tests for empty and completely filled cpumasks.

Signed-off-by Sander Vanheule <[email protected]>

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

Quoted 7 lines

---
 lib/Kconfig.debug  |   9 ++++
 lib/Makefile       |   1 +
 lib/test_cpumask.c | 115 +++++++++++++++++++++++++++++++++++++++++++++

 3 files changed, 125 insertions(+)

 create mode 100644 lib/test_cpumask.c

[..]

Quoted 7 lines

+#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.