我按照 tidb-ansible https://github.com/pingcap/tidb-ansible/blob/master/roles/systemd/templates/systemd_binary.service.j2 源代码，将 MemoryLimit 添加到inventory.ini 配置文件中，
......
# process supervision, [systemd, supervise]
process_supervision = systemd
MemoryLimit = 20G
timezone = Asia/Shanghai
......
然后执行
ansible-playbook deploy.yml && ansible-playbook rolling_update.yml