A cluster began upgrading from 4.10.28 to 4.11.5, but the control plane upgrade has stalled during upgrade of the node-tuning-operator.

The reason is that the node-tuning-operator is in a crashloop, and this appears to be because it is trying to get a list of CSVs, and this takes too long, causing a timeout:

F1016 23:19:57.077167       1 main.go:130] unable to remove Performance addons OLM operator: the server was unable to return a response in the time allotted, but may still be processing the request (get clu
sterserviceversions.operators.coreos.com)                                   goroutine 1 [running]:

The cluster has a large number of CSVs installed (29000) - it has ~1500 namespaces and each namespace has ~20 CSVs in it (a number of operators installed that will install CSVs in all namespaces)

The cluster is currently stuck because the CSV List never completes in time.

4.10.28 (upgrading from)
4.11.5 (upgrading to)