Bug 1144280 - Setting CPU limit has no effect
Summary: Setting CPU limit has no effect
Keywords:
Status: CLOSED DUPLICATE of bug 1143992
Alias: None
Product: oVirt
Classification: Retired
Component: ovirt-engine-core
Version: 3.5
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
: ---
Assignee: bugs@ovirt.org
QA Contact: Pavel Stehlik
URL:
Whiteboard: sla
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2014-09-19 06:58 UTC by Martin Perina
Modified: 2014-11-23 15:10 UTC (History)
8 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2014-11-23 15:10:28 UTC
oVirt Team: ---
Embargoed:


Attachments (Terms of Use)
engine and VDSM logs (820.09 KB, application/octet-stream)
2014-09-19 06:58 UTC, Martin Perina
no flags Details

Description Martin Perina 2014-09-19 06:58:33 UTC
Created attachment 939106 [details]
engine and VDSM logs

Description of problem:

Creating QoS to limit CPU utilization has no effect, not matter what value is used (I tested values 1, 50 and 100), if VM cpus are utilized to 100%, host CPUs are also utilized to 100%


Version-Release number of selected component (if applicable):

ovirt-engine-3.5.0-0.0.master.20140911085446.gite1c5ffd.fc19.noarch
vdsm-4.16.4-0.el6.x86_64

How reproducible:

100%

Steps to Reproduce:
1. Create a VM with the same number of CPUs as Host
2. Create CPU type QoS in DC and set the limit to desired value
3. In Cluster create new CPU profile with above QoS and remove the default CPU profile
4. Start the VM and execute (N is a number of CPUs in VM)
   stress --cpu N
5. Connect to Host and execute
   sar -u 1 10

Actual results:

Host CPUs are utilized to 100% percent no matter what limit was entered in QoS

Expected results:

Host CPUs should be utilized according to eneter QoS

Additional info:


To utilize VM CPUs I used stress tool [1]


[1] http://people.seas.harvard.edu/~apw/stress/

Comment 1 Martin Perina 2014-09-22 09:36:30 UTC
Forgot to add step between 3. and 4., correct reproduce steps are:

1. Create a VM with the same number of CPUs as Host
2. Create CPU type QoS in DC and set the limit to desired value
3. In Cluster create new CPU profile with above QoS and remove the default CPU profile
4. In Edit VM dialog, Resource Allocation tab set relevant CPU profile
5. Start the VM and execute (N is a number of CPUs in VM)
   stress --cpu N
6. Connect to Host and execute
   sar -u 1 10

Comment 2 Doron Fediuck 2014-11-23 15:10:28 UTC

*** This bug has been marked as a duplicate of bug 1143992 ***


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