The QEMU project is currently considering to move its bug tracking to
another system. For this we need to know which bugs are still valid
and which could be closed already. Thus we are setting older bugs to
"Incomplete" now.
If you still think this bug report here is valid, then please switch
the state back to "New" within the next 60 days, otherwise this report
will be marked as "Expired". Or please mark it as "Fix Released" if
the problem has been solved with a newer version of QEMU already.
Thank you and sorry for the inconvenience.
** Changed in: qemu
Status: New => Incomplete
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1829696
Title:
qemu-kvm takes 100% CPU when running redhat/centos 7.6 guest VM OS
Status in QEMU:
Incomplete
Bug description:
Description
===========
When running redhat or centos 7.6 guest os on vm,
the cpu usage is very low on vm(100% idle), but on host,
qemu-kvm reports 100% cpu busy usage.
After searching some related bugs report,
I suspect that it is due to the clock settings in vm's domain xml.
My Openstack cluster uses the default clock settings as follow:
<clock offset='utc'>
<timer name='rtc' tickpolicy='catchup'/>
<timer name='pit' tickpolicy='delay'/>
<timer name='hpet' present='no'/>
</clock>
And in this report, https://bugs.launchpad.net/qemu/+bug/1174654
it claims that <timer name='rtc' track='guest'/> can solve the 100% cpu usage
problem when using Windows Image Guest OS,
but I makes some tests, the solusion dose not work for me.
Steps to reproduce
==================
* create a vm using centos or redhat 7.6 image
* using sar tool inside vm and host to check the cpu usage, and compare them
Expected result
===============
host's cpu usage report should be same with vm's cpu usage
Actual result
=============
vm's cpu usage is 100% idle, host's cpu usage is 100% busy
Environment
===========
1. Exact version of OpenStack you are running.
# rpm -qa | grep nova
openstack-nova-compute-13.1.2-1.el7.noarch
python2-novaclient-3.3.2-1.el7.noarch
python-nova-13.1.2-1.el7.noarch
openstack-nova-common-13.1.2-1.el7.noarch
2. Which hypervisor did you use?
(For example: Libvirt + KVM, Libvirt + XEN, Hyper-V, PowerKVM, ...)
What's the version of that?
# libvirtd -V
libvirtd (libvirt) 3.9.0
# /usr/libexec/qemu-kvm --version
QEMU emulator version 2.6.0 (qemu-kvm-ev-2.6.0-28.el7_3.6.1), Copyright (c)
2003-2008 Fabrice Bellard
Logs & Configs
==============
The VM xml:
<domain type='kvm' id='29'>
<name>instance-00005022</name>
<uuid>7f5a66a5-****-****-****-75dec****bbb</uuid>
<metadata>
<nova:instance xmlns:nova="http://openstack.org/xmlns/libvirt/nova/1.0";>
<nova:package version="13.1.2-1.el7"/>
<nova:name>*******</nova:name>
<nova:creationTime>2019-05-20 03:08:46</nova:creationTime>
<nova:flavor name="2d2dab36-****-****-****-246e9****110">
<nova:memory>2048</nova:memory>
<nova:disk>12</nova:disk>
<nova:swap>2048</nova:swap>
<nova:ephemeral>0</nova:ephemeral>
<nova:vcpus>1</nova:vcpus>
</nova:flavor>
<nova:owner>
<nova:user uuid="********************">****</nova:user>
<nova:project uuid="********************">****</nova:project>
</nova:owner>
<nova:root type="image" uuid="4496a420-****-****-****-b50f****ada3"/>
</nova:instance>
</metadata>
<memory unit='KiB'>2097152</memory>
<currentMemory unit='KiB'>2097152</currentMemory>
<vcpu placement='static'>1</vcpu>
<cputune>
<shares>1024</shares>
<vcpupin vcpu='0' cpuset='27'/>
<emulatorpin cpuset='27'/>
</cputune>
<numatune>
<memory mode='strict' nodeset='1'/>
<memnode cellid='0' mode='strict' nodeset='1'/>
</numatune>
<resource>
<partition>/machine</partition>
</resource>
<sysinfo type='smbios'>
<system>
<entry name='manufacturer'>Fedora Project</entry>
<entry name='product'>OpenStack Nova</entry>
<entry name='version'>13.1.2-1.el7</entry>
<entry name='serial'>64ab0e89-****-****-****-05312ef66983</entry>
<entry name='uuid'>7f5a66a5-****-****-****-75decaf82bbb</entry>
<entry name='family'>Virtual Machine</entry>
</system>
</sysinfo>
<os>
<type arch='x86_64' machine='pc-i440fx-rhel7.3.0'>hvm</type>
<boot dev='hd'/>
<smbios mode='sysinfo'/>
</os>
<features>
<acpi/>
<apic/>
</features>
<cpu mode='custom' match='exact' check='full'>
<model fallback='forbid'>IvyBridge</model>
<topology sockets='1' cores='1' threads='1'/>
<feature policy='require' name='hypervisor'/>
<feature policy='require' name='arat'/>
<feature policy='require' name='xsaveopt'/>
<numa>
<cell id='0' cpus='0' memory='2097152' unit='KiB'/>
</numa>
</cpu>
<clock offset='utc'>
<timer name='pit' tickpolicy='delay'/>
<timer name='rtc' tickpolicy='catchup'/>
<timer name='hpet' present='no'/>
</clock>
<on_poweroff>destroy</on_poweroff>
<on_reboot>restart</on_reboot>
<on_crash>destroy</on_crash>
<devices>
<emulator>/usr/libexec/qemu-kvm</emulator>
<disk type='file' device='disk'>
<driver name='qemu' type='raw' cache='none'/>
<source
file='/data/instances/7f5a66a5-****-****-****-75decaf82bbb/disk'/>
<backingStore/>
<target dev='vda' bus='virtio'/>
<alias name='virtio-disk0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x04'
function='0x0'/>
</disk>
<disk type='file' device='disk'>
<driver name='qemu' type='raw' cache='none'/>
<source
file='/data/instances/7f5a66a5-****-****-****-75decaf82bbb/disk.swap'/>
<backingStore/>
<target dev='vdb' bus='virtio'/>
<alias name='virtio-disk1'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x05'
function='0x0'/>
</disk>
<disk type='file' device='cdrom'>
<driver name='qemu' type='raw' cache='none'/>
<source
file='/data/instances/7f5a66a5-****-****-****-75decaf82bbb/disk.config'/>
<backingStore/>
<target dev='hdd' bus='ide'/>
<readonly/>
<alias name='ide0-1-1'/>
<address type='drive' controller='0' bus='1' target='0' unit='1'/>
</disk>
<controller type='usb' index='0' model='piix3-uhci'>
<alias name='usb'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x01'
function='0x2'/>
</controller>
<controller type='pci' index='0' model='pci-root'>
<alias name='pci.0'/>
</controller>
<controller type='ide' index='0'>
<alias name='ide'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x01'
function='0x1'/>
</controller>
<interface type='bridge'>
<mac address='fa:16:3e:a6:ea:4f'/>
<source bridge='brq52c66dc3-64'/>
<bandwidth>
<inbound average='102400'/>
<outbound average='102400'/>
</bandwidth>
<target dev='tapa29e94e5-42'/>
<model type='virtio'/>
<alias name='net0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x03'
function='0x0'/>
</interface>
<serial type='file'>
<source
path='/data/instances/7f5a66a5-****-****-****-75decaf82bbb/console.log'/>
<target type='isa-serial' port='0'>
<model name='isa-serial'/>
</target>
<alias name='serial0'/>
</serial>
<serial type='pty'>
<source path='/dev/pts/10'/>
<target type='isa-serial' port='1'>
<model name='isa-serial'/>
</target>
<alias name='serial1'/>
</serial>
<console type='file'>
<source
path='/data/instances/7f5a66a5-****-****-****-75decaf82bbb/console.log'/>
<target type='serial' port='0'/>
<alias name='serial0'/>
</console>
<input type='tablet' bus='usb'>
<alias name='input0'/>
<address type='usb' bus='0' port='1'/>
</input>
<input type='mouse' bus='ps2'>
<alias name='input1'/>
</input>
<input type='keyboard' bus='ps2'>
<alias name='input2'/>
</input>
<graphics type='vnc' port='5910' autoport='yes' listen='0.0.0.0'
keymap='en-us'>
<listen type='address' address='0.0.0.0'/>
</graphics>
<video>
<model type='cirrus' vram='16384' heads='1' primary='yes'/>
<alias name='video0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x02'
function='0x0'/>
</video>
<memballoon model='virtio'>
<stats period='10'/>
<alias name='balloon0'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x06'
function='0x0'/>
</memballoon>
</devices>
<seclabel type='dynamic' model='dac' relabel='yes'>
<label>+107:+107</label>
<imagelabel>+107:+107</imagelabel>
</seclabel>
</domain>
CPU Usage Report inside VM:
# sar -u -P 0 1 5
Linux 3.10.0-957.el7.x86_64 (******) 05/20/2019 _x86_64_ (1 CPU)
11:34:40 AM CPU %user %nice %system %iowait %steal
%idle
11:34:41 AM 0 0.00 0.00 0.00 0.00 0.00
100.00
11:34:42 AM 0 0.00 0.00 0.00 0.00 0.00
100.00
11:34:43 AM 0 0.00 0.00 0.00 0.00 0.00
100.00
11:34:44 AM 0 0.00 0.00 0.00 0.00 0.00
100.00
11:34:45 AM 0 0.00 0.00 0.00 0.00 0.00
100.00
Average: 0 0.00 0.00 0.00 0.00 0.00
100.00
CPU Usage Report ON HOST(the vm's cpu is pinned on host's no.27 physic cpu):
# sar -u -P 27 1 5
Linux 3.10.0-862.el7.x86_64 (******) 05/20/2019 _x86_64_ (48 CPU)
11:34:40 AM CPU %user %nice %system %iowait %steal
%idle
11:34:41 AM 27 100.00 0.00 0.00 0.00 0.00
0.00
11:34:42 AM 27 100.00 0.00 0.00 0.00 0.00
0.00
11:34:43 AM 27 100.00 0.00 0.00 0.00 0.00
0.00
11:34:44 AM 27 100.00 0.00 0.00 0.00 0.00
0.00
11:34:45 AM 27 100.00 0.00 0.00 0.00 0.00
0.00
Average: 27 100.00 0.00 0.00 0.00 0.00
0.00
clocksource inside VM:
# cat /sys/devices/system/clocksource/clocksource0/current_clocksource
kvm_clock
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1829696/+subscriptions
