Another app is currently holding the yum lock； waiting for it to exit

Another app is currently holding the yum lock; waiting for it to exit...
  The other application is: PackageKit
    Memory : 155 M RSS (1.5 GB VSZ)
    Started: Mon Jun  7 23:03:06 2021 - 00:47 ago
    State  : Sleeping, pid: 69911

 
#可能是系统自动升级正在运行，yum在锁定状态中
 
# kill -s 9 25960
# ps aux|grep yum
root      6744  0.0  0.0 103260   900 pts/1    S+   14:59   0:00 grep yum
root     25960  0.0  0.0      0     0 ?        Z    Sep19   0:01 [yumBackend.py] <defunct>

可以通过强制关掉yum进程：
 
#rm -f /var/run/yum.pid