Bug 1144280

Summary: Setting CPU limit has no effect
Product: [Retired] oVirt Reporter: Martin Perina <mperina>
Component: ovirt-engine-coreAssignee: bugs <bugs>
Status: CLOSED DUPLICATE QA Contact: Pavel Stehlik <pstehlik>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 3.5CC: dfediuck, ecohen, gklein, iheim, lsurette, rbalakri, s.kieske, yeylon
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Whiteboard: sla
Fixed In Version: Doc Type: Bug Fix
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Last Closed: 2014-11-23 15:10:28 UTC Type: Bug
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Flags
engine and VDSM logs none

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 ***