CPUHP_MM_ZSWP_POOL_PREPARE
ret = cpuhp_setup_state_multi(CPUHP_MM_ZSWP_POOL_PREPARE,
cpuhp_remove_multi_state(CPUHP_MM_ZSWP_POOL_PREPARE);
ret = cpuhp_state_add_instance(CPUHP_MM_ZSWP_POOL_PREPARE,
cpuhp_state_remove_instance(CPUHP_MM_ZSWP_POOL_PREPARE, &pool->node);
cpuhp_state_remove_instance(CPUHP_MM_ZSWP_POOL_PREPARE, &pool->node);