<div><div>I tested two newest QEMU versions these days(v3.1.0 and v4.0.0), and sadly, the problem still happens.</div><div><br></div><div>I tried to find the reason why the qemu process take 100% usage of cpu, and collected some facts about it.</div><div>I compared the facts with other normal vm's qemu process(who's cpu usage is normal) and didn't find out any interesting result.</div><div><br></div><div>Please give me some guides to debug this problem if you could, thanks very much.</div><div>(The full content of facts is in the attachment and I also leave a message in <a href="https://bugs.launchpad.net/qemu/+bug/1829696">https://bugs.launchpad.net/qemu/+bug/1829696</a>)</div></div><div><br></div><div><div style="color:#909090;font-family:Arial Narrow;font-size:12px">------------------</div><div style="font-size:14px;font-family:Verdana;color:#000;"><div><br></div><div> Thanks a lot!</div><div>Best Regards</div><div>QianXi</div></div></div><div> </div><div><div><br></div><div><br></div><div style="font-size: 12px;font-family: Arial Narrow;padding:2px 0 2px 0;">------------------ Original ------------------</div><div style="font-size: 12px;background:#efefef;padding:8px;"><div><b>From: </b> "QianXi";<qianxi416@foxmail.com>;</div><div><b>Date: </b> Jun 21, 2019</div><div><b>To: </b> "Kashyap Chamarthy"<kchamart@redhat.com>; "1829696"<1829696@bugs.launchpad.net>; <wbr></div><div><b>Cc: </b> "openstack-discuss"<openstack-discuss@lists.openstack.org>; <wbr></div><div><b>Subject: </b> Reply： [nova]Bug #1829696: qemu-kvm process takes 100% CPU usage whenrunning redhat/centos 7.6 guest OS</div></div><div><br></div>Thanks very much. I will upgrade the virt tools software on the host and check if it still happens.
Later, I hope I could update you guys. Thanks again.
Best regards
QianXi<div style="COLOR: #000"><div style="PADDING-RIGHT: 0px; PADDING-LEFT: 0px; FONT-SIZE: 12px; PADDING-BOTTOM: 2px; PADDING-TOP: 2px; FONT-FAMILY: Arial Narrow">------------------ 原始邮件 ------------------</div><div style="PADDING-RIGHT: 8px; PADDING-LEFT: 8px; FONT-SIZE: 12px; BACKGROUND: #efefef; PADDING-BOTTOM: 8px; PADDING-TOP: 8px"><div><b>发件人:</b> "Kashyap Chamarthy"<kchamart@redhat.com><wbr></div><div><b>发送时间:</b> 2019年6月21日(星期五) 凌晨0:32</div><div><b>收件人:</b> "钱熙"<qianxi416@foxmail.com>;</div><div><b>抄送:</b> "openstack-discuss"<openstack-discuss@lists.openstack.org>;</div><div><b>主题:</b> Re: [nova]Bug #1829696: qemu-kvm process takes 100% CPU usage whenrunning redhat/centos 7.6 guest OS</div></div></div>On Thu, Jun 20, 2019 at 10:06:11PM +0800, 钱熙 wrote:<br>> Hi there,<br><br>Hi,<br><br>> <br>> I am struggling with qemu-kvm 100% CPU usage problem.<br>> When running redhat or centos 7.6 guest os on vm,<br>> the cpu usage is very low on vm(almost 100% idle when no tasks run), but on the host,<br>> qemu-kvm reports 100% cpu busy usage.<br>> <br>> <br>> https://bugs.launchpad.net/nova/+bug/1829696<br>> I opened the bug above, however it did not find some interest.<br>> <br>> <br>> After searching some related bugs report,<br>> I suspect that it is due to the clock settings in vm's domain xml.<br>> My settings are as follows:<br>> <clock offset='utc'><br>> <timer name='rtc' tickpolicy='catchup'/><br>> <timer name='pit' tickpolicy='delay'/><br>> <timer name='hpet' present='no'/><br>> </clock><br>> And details about the bug, please see https://bugs.launchpad.net/nova/+bug/1829696<br><br>I don't think it is related to clock settings at all.<br><br>> It shows that only the version 7.6 of redhat or centos affected by this bug behavior.<br>> In my cluster, it is OK for versions from redhat or centos 6.8 to 7.5.<br>> <br>> <br>> Any clue or suggestion?<br><br>Please see DanPB's response in comment#2; I agree with it. (Note that<br>I've changed the bug component from 'openstack-nova' --> 'qemu')<br><br> https://bugs.launchpad.net/qemu/+bug/1829696/comments/2<br><br><br>-- <br>/kashyap<br></div>