Bug 1261507

Summary:	KSM sleep_millisecs bellow 10ms for systems above 16GB of RAM
Product:	Red Hat Enterprise Virtualization Manager	Reporter:	rhev-integ
Component:	vdsm	Assignee:	Martin Sivák <msivak>
Status:	CLOSED ERRATA	QA Contact:	Shira Maximov <mshira>
Severity:	high	Docs Contact:
Priority:	high
Version:	3.5.3	CC:	amureini, bazulay, dfediuck, ecohen, gklein, istein, jentrena, juwu, lsurette, mavital, mgoldboi, msivak, pdwyer, rhodain, tdosek, ycui, yeylon
Target Milestone:	ovirt-3.5.6	Keywords:	EasyFix, Patch, ZStream
Target Release:	3.5.6	Flags:	juwu: needinfo- mgoldboi: Triaged+
Hardware:	All
OS:	Linux
Whiteboard:	sla
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:	1256949	Environment:
Last Closed:	2015-12-01 20:40:04 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	SLA	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1256949
Bug Blocks:

Comment 2 Shira Maximov 2015-11-05 14:07:33 UTC

verified on :
Red Hat Enterprise Virtualization Manager Version: 3.5.6.1-0.1.el6ev
vdsm-4.16.28-1.el7ev.x86_64
mom-0.4.1-5.el7ev.noarch

verification steps: 
1. create a host with 256GB :
   - have a nested environment in order to crate a VM that will be  a host in your setup  
   - in the nested environment, create a new cluster policy which the memory filter is disabled (the right up corner -> configure -> cluster policy)
   - go to clusters tab -> choose your cluster -> in the cluster policy -> choose the cluster policy that you created  
   - disable memory overcommited on the nested host - add the following line in the file /etc/sysctl.conf  :   vm.overcommit_memory = 1
   - power of the vm (nested host) 
   - edit the vm ( your nested host) - > set the memory to 262144
   - start the vm 
2. Triggered KSM - 
3. see that the ksmd process is not taking  a high amount of CPU  
4.  run != 0 and the millisec always bigger than 10

log results: 
/var/log/vdsm/mom.log: 
2015-11-05 15:46:26,923 - mom.Controllers.KSM - INFO - Updating KSM configuration: pages_to_scan:64 run:1 sleep_millisecs:10

Comment 3 Julie 2015-11-11 00:38:04 UTC

If this bug requires doc text for errata release, please provide draft text in the doc text field in the following format:

Cause:
Consequence:
Fix:
Result:

The documentation team will review, edit, and approve the text.

If this bug does not require doc text, please set the 'requires_doc_text' flag to -.

Comment 4 Julie 2015-11-16 23:25:21 UTC

Setting the requires_doc_text flag to '-' and cancelling need_info as did not get a response in time.

Kind regards,
Julie

Comment 6 errata-xmlrpc 2015-12-01 20:40:04 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://rhn.redhat.com/errata/RHBA-2015-2530.html