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[Qemu-devel] [Bug 1829696] Re: qemu-kvm takes 100% CPU when running redh
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From: |
qianxi |
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Subject: |
[Qemu-devel] [Bug 1829696] Re: qemu-kvm takes 100% CPU when running redhat/centos 7.6 guest VM OS |
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Date: |
Mon, 24 Jun 2019 05:30:37 -0000 |
I tested two newest QEMU versions these days, and sadly, the problem
still happens.
I tried to find the reason why the qemu process take 100% usage of cpu, and
collected some facts about it.
I compared the facts with other normal vm's qemu process(who's cpu usage is
normal) and didn't turn out any interesting result.
Please give me some guides to debug this problem if you could, thanks
very much.
(The full content of facts is in the attachment)
1.
======the command line to start a VM======
# ps -ef |grep 1567284 | cat
qemu 1567284 1 99 Jun21 ? 2-18:09:33 /usr/libexec/qemu-kvm
-name guest=instance-0000530a,debug-threads=on -S -object
secret,id=masterKey0,format=raw,file=/var/lib/libvirt/qemu/domain-1-instance-0000530a/master-key.aes
-machine pc-i440fx-4.0,accel=kvm,usb=off,dump-guest-core=off -cpu IvyBridge -m
2048 -realtime mlock=off -smp 1,sockets=1,cores=1,threads=1 -object
memory-backend-ram,id=ram-node0,size=2147483648,host-nodes=1,policy=bind -numa
node,nodeid=0,cpus=0,memdev=ram-node0 -uuid
60d3ad85-1004-47e7-b2cb-5cf1a029ab47 -smbios type=1,manufacturer=Fedora
Project,product=OpenStack
Nova,version=13.1.2-1.el7,serial=c0700413-4a28-4e97-85c4-66fe3ec367dc,uuid=60d3ad85-1004-47e7-b2cb-5cf1a029ab47,family=Virtual
Machine -no-user-config -nodefaults -chardev
socket,id=charmonitor,path=/var/lib/libvirt/qemu/domain-1-instance-0000530a/monitor.sock,server,nowait
-mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc,driftfix=slew
-global kvm-pit.lost_tick_policy=delay -no-hpet -no-shutdown -boot strict=on
-device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -drive
file=/data/instances/60d3ad85-1004-47e7-b2cb-5cf1a029ab47/disk,format=raw,if=none,id=drive-virtio-disk0,cache=none
-device
virtio-blk-pci,scsi=off,bus=pci.0,addr=0x4,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1
-drive
file=/data/instances/60d3ad85-1004-47e7-b2cb-5cf1a029ab47/disk.swap,format=raw,if=none,id=drive-virtio-disk1,cache=none
-device
virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk1,id=virtio-disk1
-drive
file=/data/instances/60d3ad85-1004-47e7-b2cb-5cf1a029ab47/disk.config,format=raw,if=none,id=drive-ide0-1-1,readonly=on,cache=none
-device ide-cd,bus=ide.1,unit=1,drive=drive-ide0-1-1,id=ide0-1-1 -netdev
tap,fd=27,id=hostnet0,vhost=on,vhostfd=29 -device
virtio-net-pci,netdev=hostnet0,id=net0,mac=fa:16:3e:21:2c:70,bus=pci.0,addr=0x3
-add-fd set=2,fd=31 -chardev file,id=charserial0,path=/dev/fdset/2,append=on
-device isa-serial,chardev=charserial0,id=serial0 -chardev pty,id=charserial1
-device isa-serial,chardev=charserial1,id=serial1 -device
usb-tablet,id=input0,bus=usb.0,port=1 -vnc 0.0.0.0:0 -k en-us -device
cirrus-vga,id=video0,bus=pci.0,addr=0x2 -device
virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6 -msg timestamp=on
root 1567288 2 0 Jun21 ? 00:00:01 [vhost-1567284]
root 1567291 2 0 Jun21 ? 00:00:00 [kvm-pit/1567284]
2.
===version of QEMU===
# /usr/libexec/qemu-kvm --version
QEMU emulator version 4.0.0
Copyright (c) 2003-2019 Fabrice Bellard and the QEMU Project developers
===version of libvirt===
# libvirtd -V
libvirtd (libvirt) 3.9.0
===version of kernal===
# uname -a
Linux txyz_40_92 3.10.0-862.el7.x86_64 #1 SMP Wed Mar 21 18:14:51 EDT 2018
x86_64 x86_64 x86_64 GNU/Linux
Red Hat Enterprise Linux Server (3.10.0-862.el7.x86_64) 7.5 (Maipo)
# modinfo kvm
filename: /lib/modules/3.10.0-862.el7.x86_64/kernel/arch/x86/kvm/kvm.ko.xz
license: GPL
author: Qumranet
retpoline: Y
rhelversion: 7.5
srcversion: 8A3372406CDF0ACF69A0E58
depends: irqbypass
intree: Y
vermagic: 3.10.0-862.el7.x86_64 SMP mod_unload modversions
signer: Red Hat Enterprise Linux kernel signing key
sig_key: 51:73:02:3B:F8:16:37:D7:BF:3C:51:50:13:4E:EC:84:1B:96:FD:0B
sig_hashalgo: sha256
parm: ignore_msrs:bool
parm: min_timer_period_us:uint
parm: kvmclock_periodic_sync:bool
parm: tsc_tolerance_ppm:uint
parm: lapic_timer_advance_ns:uint
parm: vector_hashing:bool
parm: halt_poll_ns:uint
parm: halt_poll_ns_grow:uint
parm: halt_poll_ns_shrink:uint
3.
===threads===
# ps -Lp 1567284
PID LWP TTY TIME CMD
1567284 1567284 ? 00:00:12 qemu-kvm
1567284 1567286 ? 00:00:00 call_rcu
1567284 1567289 ? 00:00:00 IO mon_iothread
1567284 1567290 ? 2-19:07:09 CPU 0/KVM
1567284 1567293 ? 00:00:00 vnc_worker
1567284 1637413 ? 00:00:00 worker
===top===
# top -H -p 1567284
top - 13:02:07 up 164 days, 21:53, 2 users, load average: 1.00, 1.01, 1.05
Threads: 6 total, 1 running, 5 sleeping, 0 stopped, 0 zombie
%Cpu(s): 2.1 us, 0.0 sy, 0.0 ni, 97.9 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 26353241+total, 25289752+free, 2771140 used, 7863752 buff/cache
KiB Swap: 8388604 total, 8388604 free, 0 used. 25926534+avail Mem
scroll coordinates: y = 1/6 (tasks), x = 1/12 (fields)
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1567290 qemu 20 0 6683072 647416 8336 R 99.7 0.2 4028:04 CPU 0/KVM
1567284 qemu 20 0 6683072 647416 8336 S 0.0 0.2 0:12.93 qemu-kvm
1567286 qemu 20 0 6683072 647416 8336 S 0.0 0.2 0:00.00 call_rcu
1567289 qemu 20 0 6683072 647416 8336 S 0.0 0.2 0:00.00 IO
mon_iothread
1567293 qemu 20 0 6683072 647416 8336 S 0.0 0.2 0:00.27 vnc_worker
1637464 qemu 20 0 6683072 647416 8336 S 0.0 0.2 0:00.00 worker
===htop===
....
** Attachment added: "100_cpu_usage_problem.txt"
https://bugs.launchpad.net/qemu/+bug/1829696/+attachment/5272644/+files/100_cpu_usage_problem.txt
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https://bugs.launchpad.net/bugs/1829696
Title:
qemu-kvm takes 100% CPU when running redhat/centos 7.6 guest VM OS
Status in QEMU:
New
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
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