Bug 1260381

Summary:	Incorrect behavior of power saving weight module
Product:	[oVirt] ovirt-engine	Reporter:	Artyom <alukiano>
Component:	General	Assignee:	Yanir Quinn <yquinn>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Artyom <alukiano>
Severity:	medium	Docs Contact:
Priority:	high
Version:	3.6.0	CC:	bugs, dfediuck, gklein, jtokar, lsurette, mavital, mgoldboi, rbalakri, rgolan, Rhev-m-bugs, sbonazzo, srevivo, ykaul, yquinn
Target Milestone:	ovirt-4.0.2	Keywords:	Triaged, ZStream
Target Release:	4.0.2.1	Flags:	dfediuck: ovirt-4.0.z+ mgoldboi: planning_ack+ rgolan: devel_ack+ mavital: testing_ack+
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:
Clones:	1349345 (view as bug list)		Environment:
Last Closed:	2016-08-12 14:29:58 UTC	Type:	Bug
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:
Bug Blocks:	1349345

Description Artyom 2015-09-06 09:59:40 UTC

Description of problem:
Power saving weight module not work in proper way for hosts with zero vms.

Version-Release number of selected component (if applicable):
rhevm-backend-3.6.0-0.12.master.el6.noarch

How reproducible:
Always

Steps to Reproduce:
1. Have two hosts with the same CPU arch(host_1, host_2)
2. Run vm with 1Gb on host_1
3. Change scheduler policy to power_saving with default parameters
4. Start additional vm

Actual results:
Vm start on host_2

Expected results:
Vm start on host_1

Additional info:
Problem that when host have zero vms, engine give to host score MaxSchedulerWeight - 1(999), but hosts with vms can have score bigger than(999) because expression:
"score -= vds.getMaxSchedulingMemory() / 100;" under calcEvenDistributionScore method in EvenDistributionWeightPolicyUnit class, we can have have negative score, and then under score method in PowerSavingWeightPolicyUnit class we run "score -= calcEvenDistributionScore(vds, vm, vdsGroup != null ? vdsGroup.getCountThreadsAsCores() : false);"
we can have have score bigger than MaxSchedulerWeight score.

Comment 2 Roy Golan 2015-12-16 09:55:29 UTC

Possibly a bug. Martin will take a look.

Comment 4 Red Hat Bugzilla Rules Engine 2016-07-03 10:37:19 UTC

Target release should be placed once a package build is known to fix a issue. Since this bug is not modified, the target version has been reset. Please use target milestone to plan a fix for a oVirt release.

Comment 5 Sandro Bonazzola 2016-07-12 10:05:12 UTC

Moving back to POST since this bug has been targeted to 4.0.1 but referenced patches are not included in 4.0.1 branch.
Please check this bug status and eventually re-target to 4.0.2.

Comment 6 Artyom 2016-07-24 15:04:06 UTC

Verified on rhevm-4.0.2-0.1.rc.el7ev.noarch