[CentOS] [CentOS-virt] Increase CPU usage on HV after upgrade (7.2 -> 7.3)

Sun Jan 22 15:19:52 UTC 2017
Subscriber <ml-lists at agoris.net.ua>

Hello Sandro,

Friday, January 20, 2017, 6:54:02 PM, you wrote:



> On Thu, Jan 19, 2017 at 3:40 PM, Subscriber <ml-lists at agoris.net.ua> wrote:
> Hello Sandro,

> Thursday, January 19, 2017, 12:12:25 PM, you wrote:

>> Discussed with KVM guys, here's the answer:
>> 1% per VM seems to much on idle VM; if the VM is not idle you are
>> getting better performance in exchange.  For idle VMs the difference
>> should be roughly 0.1% per VM.

> I compared the graphics load on the CPU before and after the upgrade.
> After  the  upgrade is clearly increased CPU System time load.  In all
> of this mode and load VM themselves became approximately the same.



> Can you share exact version of kvm, libvirt and qemu-kvm / qemu-kvm-ev you're using?

kvm_intel

In CentOS 7.2.1511:

kernel-3.10.0-327.36.3.el7.x86_64
qemu-kvm-1.5.3-105.el7_2.7.x86_64
libvirt-daemon-kvm-1.2.17-13.el7_2.5.x86_64

After upgrade from 7.2.1511 to 7.3.1611:
It was (after upgrading to this version, I noticed described in the first
report the situation):

kernel-3.10.0-514.2.2.el7.x86_64
qemu-kvm-1.5.3-126.el7.x86_64
libvirt-daemon-kvm-2.0.0-10.el7_3.2.x86_64

Now (as of 2017/01/22):

kernel-3.10.0-514.6.1.el7.x86_64
qemu-kvm-1.5.3-126.el7_3.3.x86_64
libvirt-daemon-kvm-2.0.0-10.el7_3.4.x86_64

It takes 1-2 days for monitoring, to determine whether the situation
has changed since the last update.