[CentOS] kvm/qemu and CPU load

Thu Jun 8 11:35:41 UTC 2017
hw <hw at gc-24.de>

Gordon Messmer wrote:
> On 06/02/2017 04:32 AM, hw wrote:
>> What may cause the high CPU load?
> Offhand, it's hard to say.  I don't see similar behavior.  Can you post the libvirt XML definitions for those VMs somewhere? pastebin maybe?  What's the output of "rpm -qa qemu\*"?


The definitions aren´t too long, I could post them here.  There´s
nothing special about them AFAICT; I disabled USB and am trying
to use kvmclock.

I´m finding the number of "Local timer interrupts" suspicious.  From
'cat /proc/interrupts' for CPU0:

Tue Jun  6 20:01:53 CEST 2017: 217433736
Thu Jun  8 13:23:04 CEST 2017: 350172149

That seems an awful lot of interrupts.  Is this normal?

There´s also a huge amount of "Rescheduling interrupts" (102113959 earlier,
now 209740910).  The VMs are pinned to CPUs, so what´s being rescheduled
so frequently?

I can observe that CPU load of the host goes up with increases in network
traffic of the guest.  Is it a bad idea to assign a bonding interface
to a bridge?

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