cpumask_first_zero
cpu = cpumask_first_zero(&portal_cpus);
cpu = cpumask_first_zero(&portal_cpus);
return cpumask_first_zero(cpumask);
KUNIT_EXPECT_EQ_MSG(test, 0, cpumask_first_zero(&mask_empty), MASK_MSG(&mask_empty));
KUNIT_EXPECT_LE_MSG(test, nr_cpu_ids, cpumask_first_zero(cpu_possible_mask),