Bug 1728176

Summary: KVM tracebacks causing significant latency to VM [rhel-7.6.z]
Product: Red Hat Enterprise Linux 7 Reporter: RAD team bot copy to z-stream <autobot-eus-copy>
Component: kernel-rtAssignee: Luis Claudio R. Goncalves <lgoncalv>
kernel-rt sub component: KVM QA Contact: Pei Zhang <pezhang>
Status: CLOSED CURRENTRELEASE Docs Contact:
Severity: high    
Priority: high CC: bhu, chayang, chhudson, dhoward, jraju, juzhang, kabbott, kernel-eus-qe, lcapitulino, lgoncalv, mtosatti, pbonzini, peterx, pezhang, qzhang, qzhao, virt-maint, yicwang
Version: 7.7Keywords: ZStream
Target Milestone: rc   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: kernel-rt-3.10.0-957.31.1.rt56.943.el7 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: 1717212 Environment:
Last Closed: 2019-10-28 15:55:40 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: 1717212    
Bug Blocks: 1730479    

Description RAD team bot copy to z-stream 2019-07-09 08:54:02 UTC 
This bug has been copied from bug #1717212 and has been proposed to be backported to 7.6 z-stream (EUS).
Comment 5 Pei Zhang 2019-08-11 08:04:17 UTC 
Verify this bug on rhel7.6.z by standard kvm-rt testing suite.

Test PASS: 24 hours cyclictest testing: Max latency is 33us.


==Results==
(1)Single VM with 1 rt vCPU:
# Min Latencies: 00006
# Avg Latencies: 00011
# Max Latencies: 00029

(2)Single VM with 8 rt vCPUs:
# Min Latencies: 00006 00009 00009 00009 00009 00009 00009 00009
# Avg Latencies: 00012 00009 00009 00009 00009 00009 00009 00009
# Max Latencies: 00033 00028 00027 00028 00027 00027 00027 00027

(3)Multiple VMs each with 1 rt vCPU:
- VM1
# Min Latencies: 00006
# Avg Latencies: 00011
# Max Latencies: 00031

- VM2
# Min Latencies: 00006
# Avg Latencies: 00011
# Max Latencies: 00031

- VM3
# Min Latencies: 00006
# Avg Latencies: 00011
# Max Latencies: 00031

- VM4
# Min Latencies: 00006
# Avg Latencies: 00011
# Max Latencies: 00031


==Versions==
kernel-rt-3.10.0-957.33.1.rt56.945.el7.x86_64
libvirt-4.5.0-10.el7_6.12.x86_64
qemu-kvm-rhev-2.12.0-18.el7_6.7.x86_64
tuned-2.10.0-6.el7_6.4.noarch


Move to 'VERIFIED'.