kubernetes: kubectl drain uses 200% cpu.

Running :

kubectl drain node/XXX --force=true --delete-local-data=true --ignore-daemonsets

cpu usage goes to 2 cores @ 100%

What you expected to happen: Way lower cpu usage.

Environment:

• Kubernetes version (use kubectl version):

Client Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.6", GitCommit:"dff82dc0de47299ab66c83c626e08b245ab19037", GitTreeState:"clean", BuildDate:"2020-07-15T16:58:53Z", GoVersion:"go1.13.9", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"16+", GitVersion:"v1.16.9-gke.6", GitCommit:"14bc8ad5f8c245f1240a8e4eab128c4d51bfeffe", GitTreeState:"clean", BuildDate:"2020-05-30T02:07:03Z", GoVersion:"go1.13.9b4", Compiler:"gc", Platform:"linux/amd64"}

• Cloud provider or hardware configuration: GKE
• OS (e.g: cat /etc/os-release):

NAME="Ubuntu"
VERSION="18.04.4 LTS (Bionic Beaver)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 18.04.4 LTS"
VERSION_ID="18.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=bionic
UBUNTU_CODENAME=bionic

• Kernel (e.g. uname -a): Linux felix-Latitude-7490 5.3.0-62-generic #56~18.04.1-Ubuntu SMP Wed Jun 24 16:17:03 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux