Bug 1631754 - Update to latest kernel-2.6.32-754.3.5 for RHEL 6 sees only 1 CPUn on VM.
Summary: Update to latest kernel-2.6.32-754.3.5 for RHEL 6 sees only 1 CPUn on VM.
Keywords:
Status: CLOSED DUPLICATE of bug 1623255
Alias: None
Product: Red Hat Enterprise Linux 6
Classification: Red Hat
Component: qemu-kvm
Version: 6.10
Hardware: All
OS: Linux
unspecified
medium
Target Milestone: rc
: ---
Assignee: Igor Mammedov
QA Contact: Virtualization Bugs
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2018-09-21 13:33 UTC by Gajanan
Modified: 2018-12-03 09:03 UTC (History)
9 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Environment:
Last Closed: 2018-12-03 09:03:07 UTC
Target Upstream Version:


Attachments (Terms of Use)


Links
System ID Priority Status Summary Last Updated
Red Hat Knowledge Base (Solution) 3619551 None None None 2018-09-21 13:34:45 UTC

Description Gajanan 2018-09-21 13:33:57 UTC
Description of problem:

I was able to reproduce this issue in my test environment: 

Installed a RHEL 7.5 KVM HOST. 

Further installed a RHEL 6.9 vm with 1 Core, 2 Threads, below are the outputs on it. 

# uname -a
Linux rhel610 2.6.32-696.el6.x86_64 #1 SMP Tue Feb 21 00:53:17 EST 2017 x86_64 x86_64 x86_64 GNU/Linux

# uname -r
2.6.32-696.el6.x86_64

# lscpu
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                2
On-line CPU(s) list:   0,1  <<<<<<<
Thread(s) per core:    2  <<<<<<< 
Core(s) per socket:    1
Socket(s):             1
NUMA node(s):          1
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 60
Model name:            Intel Core Processor (Haswell)
Stepping:              1
CPU MHz:               2397.222
BogoMIPS:              4794.44
Hypervisor vendor:     KVM
Virtualization type:   full
L1d cache:             32K
L1i cache:             32K
L2 cache:              4096K
NUMA node0 CPU(s):     0,1

# Then ran yum update -y on the machine and rebooted it: 

# uname -r
2.6.32-754.3.5.el6.x86_64

# uname -a
Linux rhel610 2.6.32-754.3.5.el6.x86_64 #1 SMP Thu Aug 9 11:56:22 EDT 2018 x86_64 x86_64 x86_64 GNU/Linux

# lscpu 
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                2
On-line CPU(s) list:   0  <<<<<<<
Off-line CPU(s) list:  1   <<<<<<<
Thread(s) per core:    1   <<<<<<<
Core(s) per socket:    1
Socket(s):             1
NUMA node(s):          1
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 60
Model name:            Intel Core Processor (Haswell)
Stepping:              1
CPU MHz:               2397.222
BogoMIPS:              4794.44
Hypervisor vendor:     KVM
Virtualization type:   full
L1d cache:             32K
L1i cache:             32K
L2 cache:              4096K
NUMA node0 CPU(s):     0



How reproducible:


Steps to Reproduce:
1. Installed a RHEL 7.5 kvm host
2. Then installed RHEL 6.9 vm with 1 Core, 2 Threads, verify this in lscpu command 
3. Upgrade the system to latest version i.e RHEL 6.10, after upgrading see only 1 thread and cpu, see highlighted part here.  

Actual results:

Got: 1 Core, 1 Thread after upgrade to 2.6.32-754.3.5.el6.x86_64

Expected results:

Expected: 1 Core, 2 Threads after the upgrade

Additional info: 

Customer have tested this on Hypervisor with RHEL 6 and Hypervisor with RHEL 7 both the same issue is seen.

Comment 5 Igor Mammedov 2018-12-03 09:03:07 UTC
Fixed since:
RHSA-2018:2846
https://errata.devel.redhat.com/advisory/36130
kernel-2.6.32-754.6.1.el6

*** This bug has been marked as a duplicate of bug 1623255 ***


Note You need to log in before you can comment on or make changes to this bug.