Bug 1670275

Summary: RT guest fails to boot
Product: Red Hat Enterprise Linux 7 Reporter: Pei Zhang <pezhang>
Component: tunedAssignee: Jaroslav Škarvada <jskarvad>
Status: CLOSED DUPLICATE QA Contact: qe-baseos-daemons
Severity: urgent Docs Contact:
Priority: urgent    
Version: 7.7CC: bhu, chayang, daolivei, jeder, jraju, jskarvad, juzhang, lcapitulino, lgoncalv, michen, mtosatti, olysonek, pezhang, thozza, virt-maint, williams
Target Milestone: rcKeywords: Regression
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2019-03-06 13:56:24 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: 1672377    
Attachments:
Description Flags
XML of guest
none
tuned_isolate_vcpu_thread_only.patch none

Description Pei Zhang 2019-01-29 06:30:33 UTC 
Created attachment 1524472 [details]
XML of guest

Description of problem:
RT guest fails to reboot in RT host.

Version-Release number of selected component (if applicable):
3.10.0-993.rt56.950.el7.x86_64
qemu-kvm-rhev-2.12.0-21.el7.x86_64
libvirt-4.5.0-10.el7.x86_64

How reproducible:
2/2

Steps to Reproduce:
1. Install a rhel7.7 host and setup rt environment.

3. Install a rhel7.7 guest.

4. In guest, do rt setup, then shutdown it.

5. Boot rt guest, fail.


Actual results:
RT guest fails to boot.

Expected results:
RT guest should boot successfully.

Additional info:
1. If removing below line from XML, guest can boot successfully. 
<vcpusched priority="1" scheduler="fifo" vcpus="0-1" />

2. This should be regression bug.
kernel-rt-3.10.0-993.rt56.948.el7.x86_64 works well.

3. Set this bug critical priority because it blocks all rhel7.7 kvm-rt testing.
Comment 6 Marcelo Tosatti 2019-02-04 15:22:59 UTC 
The patch that fixes the following bug:

https://bugzilla.redhat.com/show_bug.cgi?id=1554851

Fixes this problem.

Jaroslav, can you please include it in the next RHEL-7.7 tuned update? 

TIA.
Comment 7 Marcelo Tosatti 2019-02-04 17:55:04 UTC 
Created attachment 1526854 [details]
tuned_isolate_vcpu_thread_only.patch
Comment 8 Marcelo Tosatti 2019-02-04 17:56:29 UTC 
To fix the bug without a new tuned package:

# cd /usr/lib/tuned/realtime-virtual-host/

# patch -p3 < ~/tuned_isolate_vcpu_thread_only.patch

And restart tuned.
Comment 9 Pei Zhang 2019-02-11 02:36:27 UTC 
(In reply to Marcelo Tosatti from comment #8)
> To fix the bug without a new tuned package:
> 
> # cd /usr/lib/tuned/realtime-virtual-host/
> 
> # patch -p3 < ~/tuned_isolate_vcpu_thread_only.patch
> 
> And restart tuned.

Applying this tuned patch as a workaround, the rt guest can boot up well. Thanks Marcelo.


Best regards,
Pei
Comment 11 Jaroslav Škarvada 2019-03-06 13:56:24 UTC 
I am closing this as a dupe of bug 1554851, because it's resolved by the same patch.

*** This bug has been marked as a duplicate of bug 1554851 ***