Description of problem: Removing a pod with open listening sockets in a worker with a tuned profile hangs the worker Version-Release number of selected component (if applicable): OCP: 4.11.0-0.nightly-2022-06-25-081133 How reproducible: 100% Steps to Reproduce: 1. Create a tuned profile: apiVersion: tuned.openshift.io/v1 kind: Tuned metadata: name: openshift-ingress-performance namespace: openshift-cluster-node-tuning-operator spec: profile: - data: | [main] summary=Ingress performance profile include=openshift [sysctl] net.ipv4.ipfrag_time=0 net.ipv4.ipfrag_high_thresh=33554432 net.ipv4.ipfrag_low_tresh=9437184 name: openshift-ingress-performance recommend: - match: - label: node-role.kubernetes.io/worker priority: 10 profile: openshift-ingress-performance 2. Create an iperf server pod: apiVersion: v1 kind: Pod metadata: name: iperf-server spec: nodeName: worker000-r640 hostNetwork: true containers: - name: server image: quay.io/sronanrh/iperf 3. Start the iperf server: $ oc exec -it iperf-server -- iperf3 -s 4. Remove the pod $ oc delete po iperf-server Actual results: The worker were the iperf pod was running hangs in NotReady state: $ oc get node NAME STATUS ROLES AGE VERSION master-0 Ready master 15d v1.24.0+284d62a master-1 Ready master 15d v1.24.0+284d62a master-2 Ready master 15d v1.24.0+284d62a worker000-r640 NotReady worker 15d v1.24.0+284d62a <=== worker001-r640 Ready worker 15d v1.24.0+284d62a Expected results: No worker gets NoReady state
It looks like net.ipv4.ipfrag_time=0 was the culprit. With net.ipv4.ipfrag_time=1 we can not reproduce this behaviour. Closing the BZ.