yum 安装 提示错误

提示信息：

Another app is currently holding the yum lock; waiting for it to exit...
  The other application is: PackageKit 
    Memory :  27 M RSS ( 74 MB VSZ)
    Started: Wed Jun  6 22:59:02 2018 - 03:47 ago
    State  : Sleeping,pid: 2884

解决

rm -f /var/run/yum.pid