Bug 1905492

Summary: The stalld service has a higher scheduler priority than ksoftirq and rcu{b, c} threads
Product: OpenShift Container Platform Reporter: Artyom <alukiano>
Component: Performance Addon OperatorAssignee: Martin Sivák <msivak>
Status: CLOSED ERRATA QA Contact: Gowrishankar Rajaiyan <grajaiya>
Severity: high Docs Contact:
Priority: unspecified    
Version: 4.7CC: aos-bugs, grajaiya, mniranja, shajmakh
Target Milestone: ---   
Target Release: 4.7.0   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: No Doc Update
Doc Text:
Story Points: ---
Clone Of:
: 1960386 1985365 (view as bug list) Environment:
Last Closed: 2021-02-24 15:41:14 UTC Type: Bug
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:    
Bug Blocks: 1960386, 1985371    

Description Artyom 2020-12-08 13:46:08 UTC
Description of problem:
The stalld service has higher scheduler priority than ksoftirq and rcu{b, c} threads, that can lead to the system freeze when running load intensive processes as oslat.

Version-Release number of selected component (if applicable):
Client Version: 4.6.0-0.nightly-2020-07-25-091217
Server Version: 4.7.0-0.ci-2020-12-08-050547
Kubernetes Version: v1.19.2-1007+ad738ba548b6d6-dirty

How reproducible:
Always

Steps to Reproduce:
1. run oslat tool on the node to create pressure on the real-time kernel environment
2.
3.

Actual results:
The host will be freeze until the oslat will finish running

Expected results:
The host should continue to work as expected.


Additional info:

Comment 4 Niranjan Mallapadi Raghavender 2020-12-28 10:10:44 UTC
Version:
--------

[root@dell-r730-009 cnf-internal-deploy]# oc version
Client Version: 4.7.0-0.nightly-2020-12-04-013308
Server Version: 4.7.0-0.nightly-2020-12-21-131655
Kubernetes Version: v1.20.0+87544c5


Version of Performance Operator:
---------------------------------
rh-osbs/openshift4-performance-addon-operator-bundle-registry-container-rhel8:v4.7.0-285
Index image v4.7: registry-proxy.engineering.redhat.com/rh-osbs/iib:34633
[root@dell-r730-009 cnf-internal-deploy]# oc logs pods/performance-operator-767ddb449-lknqr -n openshift-performance-addon-operator
I1228 07:50:49.908341       1 main.go:72] Operator Version:
I1228 07:50:49.908453       1 main.go:73] Git Commit:
I1228 07:50:49.908461       1 main.go:74] Build Date: 2020-12-22T13:00:05+0000
I1228 07:50:49.908475       1 main.go:75] Go Version: go1.13.15
I1228 07:50:49.908481       1 main.go:76] Go OS/Arch: linux/amd64
I1228 07:50:50.962708       1 request.go:621] Throttling request took 1.036451752s, request: GET:https://172.30.0.1:443/apis/tuned.openshift.io/v1?timeout=32s

Deployed performance profile and checked the tuned profile pod and it contains the relevant information. 


[main]
summary=Openshift node optimized for deterministic performance at the cost of increased power consumption, focused on low latency network performance. Based on Tuned 2.11 and Cluster node tuning (oc 4.5)
include=openshift-node,cpu-partitioning   

[variables]

isolated_cores=2-15

not_isolated_cores_expanded=${f:cpulist_invert:${isolated_cores_expanded}}

[cpu]
force_latency=cstate.id:1|3                   #  latency-performance  (override)
governor=performance                          #  latency-performance 
energy_perf_bias=performance                  #  latency-performance 
min_perf_pct=100                              #  latency-performance 

[service]
service.stalld=start,enable

[vm]
transparent_hugepages=never                   #  network-latency
[scheduler]
group.ksoftirqd=0:f:11:*:ksoftirqd.*
group.rcuc=0:f:11:*:rcuc.*

Marking it verified.

Comment 6 errata-xmlrpc 2021-02-24 15:41:14 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 4.7.0 security, bug fix, and enhancement 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-2020:5633