Hi Bart.

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Hi, Marcelo 

Actually we met this message before in bug 855245. And in the old bug 855245 there's other critical issue except the dmesg and finally the critical issue got fixed.  And in the bug 855245#c2 you said it's harmless about the dmesg.  Could you help check this bug again, whether we need to fix this?  

Thanks!
Qunfang

Qunfang Zhang, the message is harmless as kvmclock is able to handle the TSC frequency change.


Bart Verwilst, a patch has been submitted to print the warning message once.

This request was evaluated by Red Hat Product Management for
inclusion in a Red Hat Enterprise Linux release.  Product
Management has requested further review of this request by
Red Hat Engineering, for potential inclusion in a Red Hat
Enterprise Linux release for currently deployed products.
This request is not yet committed for inclusion in a release.

Patch(es) available on kernel-2.6.32-403.el6

reproduce this issue with kernel version(2.6.32-379.el6.x86_64 :  src and des rhel6.5 host)
hostA: 
model name: Intel(R) Core(TM)2 Quad CPU    Q9400  @ 2.66GHz
hostB:
model name: Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz
guest version:  rhel6.3 && rhel6.4

Steps to Reproduce:
1. boot src guest on hostA:
/usr/libexec/qemu-kvm -M pc -cpu SandyBridge -enable-kvm -m 4G -smp 2,sockets=1,cores=2,threads=2 -name scalability-test -rtc base=localtime,clock=host,driftfix=slew  -k en-us  -boot menu=on -spice disable-ticketing,port=5931 -vga cirrus -monitor stdio -device virtio-balloon-pci,id=ballooning  -qmp tcp:0:7777,server,nowait -usb -device usb-tablet  -drive file=/mnt/RHEL-Server-6.3-64.qcow2,if=none,id=drive-system-disk,media=disk,format=qcow2,aio=native,werror=stop,rerror=stop -device virtio-blk-pci,scsi=on,bus=pci.0,drive=drive-system-disk,id=system-disk,bootindex=1,addr=0x5      -netdev tap,id=hostnet0,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet0,id=virtio-net-pci0,mac=00:22:15:27:54:9d,bus=pci.0,addr=0x9

2. listening on hostB:
/usr/libexec/qemu-kvm -M pc -cpu SandyBridge -enable-kvm -m 4G -smp 2,sockets=1,cores=2,threads=2 -name scalability-test -rtc base=localtime,clock=host,driftfix=slew  -k en-us  -boot menu=on -spice disable-ticketing,port=5931 -vga cirrus -monitor stdio -device virtio-balloon-pci,id=ballooning  -qmp tcp:0:7777,server,nowait -usb -device usb-tablet  -drive file=/mnt/RHEL-Server-6.3-64.qcow2,if=none,id=drive-system-disk,media=disk,format=qcow2,aio=native,werror=stop,rerror=stop -device virtio-blk-pci,scsi=on,bus=pci.0,drive=drive-system-disk,id=system-disk,bootindex=1,addr=0x5      -netdev tap,id=hostnet0,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet0,id=virtio-net-pci0,mac=00:22:15:27:54:9d,bus=pci.0,addr=0x9  -incoming tcp:0:5888

3. migrate from src to des
migrate -d tcp:$des_host_ip:5888

4. tail /var/log/messages

Actual results:
after migration, the des guest logs start to get flooded ( 2 lines every second ) with lines like this:
Aug  2 05:44:27 localhost kernel: Clocksource tsc unstable (delta = 137649824 ns).  Enable clocksource failover by adding clocksource_failover kernel parameter.
Aug  2 05:44:28 localhost kernel: Clocksource tsc unstable (delta = 137654743 ns).  Enable clocksource failover by adding clocksource_failover kernel parameter.
Aug  2 05:44:28 localhost kernel: Clocksource tsc unstable (delta = 137655477 ns).  Enable clocksource failover by adding clocksource_failover kernel parameter.
Aug  2 05:44:29 localhost kernel: Clocksource tsc unstable (delta = 137708230 ns).  Enable clocksource failover by adding clocksource_failover kernel parameter.
Aug  2 05:44:29 localhost kernel: Clocksource tsc unstable (delta = 137601539 ns).  Enable clocksource failover by adding clocksource_failover kernel parameter.

Expected results:
Only show one information.




Verify this issue with guest kernel version (2.6.32-403.el6.x86_64 )
host kernel：
2.6.32-403.el6.x86_64  &&  2.6.32-379.el6.x86_64
Steps as above.

Actual results: 
only show one information(tail /var/log/messages)

Based on above information, so I think this bug has benn fixed.

is there an eta for the new kernel to be released?

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHSA-2013-1645.html