KMEM_ZBASE
size = (size & ~KMEM_ZMASK) + KMEM_ZBASE;
for (; i <= size; i+= KMEM_ZBASE)
#define KMEM_ZMASK (KMEM_ZBASE - 1)
size = (size & ~KMEM_ZMASK) + KMEM_ZBASE;
size = (size & ~KMEM_ZMASK) + KMEM_ZBASE;