Bug 700694

Summary: guest time drift under load
Product: Red Hat Enterprise Linux 5 Reporter: Xiaoqing Wei <xwei>
Component: kvmAssignee: Virtualization Maintenance <virt-maint>
Status: CLOSED NOTABUG QA Contact: Virtualization Bugs <virt-bugs>
Severity: medium Docs Contact:
Priority: medium    
Version: 5.7CC: akong, juzhang, mkenneth, virt-maint
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-05-13 08:41:49 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Xiaoqing Wei 2011-04-29 03:23:12 UTC 
Description of problem:
boot a guest,run load on it for a while,guest will time drift for a few seconds

Version-Release number of selected component (if applicable):
kvm-83-224.el5_6.1

How reproducible:

mostly
Steps to Reproduce:
1.boot a guest by :
qemu-kvm -name 'vm1' -monitor stdio .....


2.run load on guest ,eg: play hd video 
3.
  
Actual results:
guest time drift

Expected results:
guest time accurate

Additional info:

kernel-2.6.18-238.9.1.el5
kvm-83-224.el5_6.1



guest info :OS WINXP
full cmd :
qemu-kvm -name 'vm1' -monitor stdio -serial unix:'/tmp/serial-20110425-144552-JMbU',server,nowait -drive file='/usr/local/staf/test/RHEV/kvm/autotest/client/tests/kvm/images/winXP-32.qcow2',index=0,if=ide,media=disk,cache=none,format=qcow2 -net nic,vlan=0,model=rtl8139,macaddr='9a:b5:b1:9b:f2:ac' -net tap,vlan=0,ifname='t0-144552-JMbU',script='/usr/local/staf/test/RHEV/kvm/autotest/client/tests/kvm/scripts/qemu-ifup-switch',downscript='no' -m 32768 -smp 4,cores=1,threads=1,sockets=4 -drive file='/usr/local/staf/test/RHEV/kvm/autotest/client/tests/kvm/isos/windows/winutils.iso',media=cdrom,index=1 -cpu qemu64,+sse2 -soundhw ac97 -redir tcp:5001::10023 -spice port=8001,disable-ticketing -qxl 1 -rtc-td-hack -M rhel5.6.0 -boot c  -usbdevice tablet
Comment 1 Xiaoqing Wei 2011-05-09 03:12:48 UTC 
also hit this issue on :
kernel-2.6.18-259.el5
kvm-83-232.el5
Comment 2 Xiaoqing Wei 2011-05-13 08:41:49 UTC 
time drift approx. 2.x sec, is acceptable.close this bug