Bug 1973237

Summary:	RHCOS-shipped stalld systemd units do not use SCHED_FIFO to run stalld.
Product:	OpenShift Container Platform	Reporter:	OpenShift BugZilla Robot <openshift-bugzilla-robot>
Component:	Node Tuning Operator	Assignee:	Jiří Mencák <jmencak>
Status:	CLOSED ERRATA	QA Contact:	Simon <skordas>
Severity:	high	Docs Contact:
Priority:	high
Version:	4.9	CC:	jmencak, jrouth, sejug
Target Milestone:	---
Target Release:	4.8.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	No Doc Update
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-07-27 23:13:09 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1973154
Bug Blocks:	1972701

Comment 2 Simon 2021-06-22 12:39:37 UTC

$ oc get clusterversions.config.openshift.io 
NAME      VERSION                             AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.8.0-0.nightly-2021-06-22-022125   True        False         84m     Cluster version is 4.8.0-0.nightly-2021-06-22-022125

$ oc get nodes
NAME                                         STATUS   ROLES    AGE    VERSION
ip-10-0-147-196.us-east-2.compute.internal   Ready    master   108m   v1.21.0-rc.0+120883f
ip-10-0-154-170.us-east-2.compute.internal   Ready    worker   103m   v1.21.0-rc.0+120883f
ip-10-0-165-195.us-east-2.compute.internal   Ready    master   109m   v1.21.0-rc.0+120883f
ip-10-0-185-57.us-east-2.compute.internal    Ready    worker   103m   v1.21.0-rc.0+120883f
ip-10-0-203-159.us-east-2.compute.internal   Ready    worker   103m   v1.21.0-rc.0+120883f
ip-10-0-221-205.us-east-2.compute.internal   Ready    master   109m   v1.21.0-rc.0+120883f

$ node=ip-10-0-154-170.us-east-2.compute.internal

$ oc label node $node node-role.kubernetes.io/worker-rt= --overwrite
node/ip-10-0-154-170.us-east-2.compute.internal labeled

$ oc get nodes
NAME                                         STATUS   ROLES              AGE    VERSION
ip-10-0-147-196.us-east-2.compute.internal   Ready    master             110m   v1.21.0-rc.0+120883f
ip-10-0-154-170.us-east-2.compute.internal   Ready    worker,worker-rt   104m   v1.21.0-rc.0+120883f
ip-10-0-165-195.us-east-2.compute.internal   Ready    master             110m   v1.21.0-rc.0+120883f
ip-10-0-185-57.us-east-2.compute.internal    Ready    worker             104m   v1.21.0-rc.0+120883f
ip-10-0-203-159.us-east-2.compute.internal   Ready    worker             104m   v1.21.0-rc.0+120883f
ip-10-0-221-205.us-east-2.compute.internal   Ready    master             110m   v1.21.0-rc.0+120883f

$ oc create -f https://raw.githubusercontent.com/openshift/cluster-node-tuning-operator/master/test/e2e/testing_manifests/stalld.yaml

tuned.tuned.openshift.io/openshift-realtime created

$ oc create -f https://raw.githubusercontent.com/openshift/cluster-node-tuning-operator/master/examples/realtime-mcp.yaml

machineconfigpool.machineconfiguration.openshift.io/worker-rt created

$ oc debug node/$node
Starting pod/ip-10-0-154-170us-east-2computeinternal-debug ...
To use host binaries, run `chroot /host`
Pod IP: 10.0.154.170
If you don't see a command prompt, try pressing enter.
sh-4.4# 
sh-4.4# 
sh-4.4# ps -efL | grep stalld
root        3999       1    3999  0    1 12:29 ?        00:00:00 /usr/local/bin/stalld --systemd -p 1000000000 -r 10000 -d 3 -t 20 --log_syslog --log_kmsg --foreground --pidfile /run/stalld.pid
root       13014   12248   13014  0    1 12:34 pts/0    00:00:00 grep stalld
sh-4.4# chrt -ap 3999
pid 3999's current scheduling policy: SCHED_FIFO
pid 3999's current scheduling priority: 10

Comment 6 errata-xmlrpc 2021-07-27 23:13:09 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (Moderate: OpenShift Container Platform 4.8.2 bug fix and security update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2021:2438