mempool_prepare_kmalloc
extra_elem = mempool_prepare_kmalloc(test, &pool, size);
extra_elem = mempool_prepare_kmalloc(test, &pool, size);
extra_elem = mempool_prepare_kmalloc(test, &pool, size);
extra_elem = mempool_prepare_kmalloc(test, &pool, size);
extra_elem = mempool_prepare_kmalloc(test, &pool, size);
extra_elem = mempool_prepare_kmalloc(test, &pool, size);
extra_elem = mempool_prepare_kmalloc(test, &pool, size);
extra_elem = mempool_prepare_kmalloc(test, &pool, size);