[CentOS-virt] [CentOS] qemu-kvm high cpu usage with idle windows guest

Sun Apr 7 15:45:18 UTC 2013
Micky <mickylmartin at gmail.com>

On Sun, Apr 7, 2013 at 8:32 PM, Zoltan Frombach <zoltan at frombach.com> wrote:
> Check out these threads they may help you solve your issue with Windows VMs:

Well I did. Upstream provides rpms till version 0.12.1.x. Even the
RHEV srpm (the one I am using) has the same version. And I don't want
to compile both libvirt and qemu-kvm from source since it is the
production machine.

> http://forum.proxmox.com/threads/5770-Windows-guest-high-context-switch-rate-when-idle
>
> http://serverfault.com/questions/146922/why-is-idle-windows-vm-using-so-much-cpu


>
> On 4/7/2013 5:18 PM, Banyan He wrote:
>> Maybe you can print out what it is doing, then try to figure out if they
>> are doing good. My linux works good, never tried windows.
>>

Did. Nothing abnormal.
A quick perf shows this:

# ........  ........  ..................
..............................................
#
     4.96%  qemu-kvm  [kvm]               [k] kvm_arch_vcpu_ioctl_run
     4.83%  qemu-kvm  [kvm_intel]         [k] vmx_vcpu_run
     4.47%  qemu-kvm  [kernel.kallsyms]   [k] find_busiest_group
     3.23%  qemu-kvm  [kernel.kallsyms]   [k] _spin_lock
     3.10%  qemu-kvm  [kernel.kallsyms]   [k] native_write_msr_safe
     1.24%  qemu-kvm  [kernel.kallsyms]   [k] _spin_lock_irq
     1.22%  qemu-kvm  [kvm]               [k] paging64_walk_addr
     1.21%  qemu-kvm  [kvm]               [k] x86_decode_insn
     1.21%  qemu-kvm  [kvm_intel]         [k] vmcs_writel

>> Banyan He