Bug 1498148

Summary:	realtime-virtual-host: disable ksm
Product:	Red Hat Enterprise Linux 7	Reporter:	Luiz Capitulino <lcapitulino>
Component:	tuned	Assignee:	Luiz Capitulino <lcapitulino>
Status:	CLOSED ERRATA	QA Contact:	Tereza Cerna <tcerna>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	7.5	CC:	jeder, jskarvad, olysonek, ovasik, pezhang, tcerna
Target Milestone:	rc	Keywords:	Patch, Upstream
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	tuned-2.9.0-1.el7	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2018-04-10 16:07:06 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:	1467576
Bug Blocks:	1240765

Description Luiz Capitulino 2017-10-03 14:43:20 UTC

Description of problem:

KSM is enabled by default when the qemu-kvm-common-rhev package is installed. Its execution is controlled by a service called ksmtuned. Although ksmtuned will only run ksm when qemu's memory consumption reaches a certain threshold (which I don't know if it accounts for hugeTLB pages) we should disable KSM not run in the risk of getting latency spikes.


Version-Release number of selected component (if applicable): tuned-2.8.0-5.el7.noarch


How reproducible:


Steps to Reproduce:
1. Boot a KVM-RT host
2. Run "systemctl status ksmtuned", if this is running then it's enabled

Comment 2 Luiz Capitulino 2017-10-05 18:31:13 UTC

Posted series downstream a few days ago. I can upload it here if needed.

Comment 3 Jaroslav Škarvada 2017-10-12 08:29:58 UTC

Upstream commit:
https://github.com/redhat-performance/tuned/commit/03449e60f9e9214707ab55380b87b39a8cd63f38

Comment 6 Tereza Cerna 2018-01-15 11:50:36 UTC

======================================================
Verified in:
    tuned-2.9.0-1.el7.noarch
    tuned-profiles-cpu-partitioning-2.9.0-1.el7.noarch
    tuned-profiles-nfv-host-2.9.0-1.el7.noarch
PASS
======================================================

# systemctl status ksm ksmtuned
● ksm.service - Kernel Samepage Merging
   Loaded: loaded (/usr/lib/systemd/system/ksm.service; enabled; vendor preset: enabled)
   Active: active (exited) since Mon 2018-01-15 10:30:20 CET; 188s ago
● ksmtuned.service - Kernel Samepage Merging (KSM) Tuning Daemon
   Loaded: loaded (/usr/lib/systemd/system/ksmtuned.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2018-01-15 10:30:20 CET; 188s ago

# tuned-adm profile cpu-partitioning

# systemctl status ksm ksmtuned
● ksm.service - Kernel Samepage Merging
   Loaded: loaded (/usr/lib/systemd/system/ksm.service; disabled; vendor preset: enabled)
   Active: inactive (dead)
● ksmtuned.service - Kernel Samepage Merging (KSM) Tuning Daemon
   Loaded: loaded (/usr/lib/systemd/system/ksmtuned.service; disabled; vendor preset: enabled)
   Active: inactive (dead)

>> Services ksm and ksmtuned are disabled and inactive.

# tuned-adm profile balanced

# systemctl status ksm ksmtuned
● ksm.service - Kernel Samepage Merging
   Loaded: loaded (/usr/lib/systemd/system/ksm.service; enabled; vendor preset: enabled)
   Active: active (exited) since Mon 2018-01-15 10:48:38 CET; 3s ago
● ksmtuned.service - Kernel Samepage Merging (KSM) Tuning Daemon
   Loaded: loaded (/usr/lib/systemd/system/ksmtuned.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2018-01-15 10:48:38 CET; 3s ago

>> Services ksm and ksmtuned are enabled and started again.

======================================================
Reproduced in:
    tuned-2.8.0-5.el7.noarch
    tuned-profiles-cpu-partitioning-2.8.0-5.el7.noarch
    tuned-profiles-nfv-host-2.8.0-5.el7.noarch
FAIL
======================================================

# systemctl status ksm ksmtuned
● ksm.service - Kernel Samepage Merging
   Loaded: loaded (/usr/lib/systemd/system/ksm.service; enabled; vendor preset: enabled)
   Active: active (exited) since Mon 2018-01-15 10:48:38 CET; 1h 59min ago
● ksmtuned.service - Kernel Samepage Merging (KSM) Tuning Daemon
   Loaded: loaded (/usr/lib/systemd/system/ksmtuned.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2018-01-15 10:48:38 CET; 1h 59min ago

# tuned-adm profile cpu-partitioning

# systemctl status ksm ksmtuned
● ksm.service - Kernel Samepage Merging
   Loaded: loaded (/usr/lib/systemd/system/ksm.service; enabled; vendor preset: enabled)
   Active: active (exited) since Mon 2018-01-15 10:48:38 CET; 1h 59min ago
● ksmtuned.service - Kernel Samepage Merging (KSM) Tuning Daemon
   Loaded: loaded (/usr/lib/systemd/system/ksmtuned.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2018-01-15 10:48:38 CET; 1h 59min ago

>> Services ksm and ksmtuned should be disabled and inactive and it is not true. FAIL.

Comment 11 errata-xmlrpc 2018-04-10 16:07:06 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, 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/RHBA-2018:0879