[vfio-users] cpu usage in guest != cpu usage in host, even with exclusive pinning

Alex Williamson alex.l.williamson at gmail.com
Mon Apr 4 01:07:50 UTC 2016

If this is the issue I think it is, the unraid folks bisected this and
found the culprit as:

aca6ff2 KVM: dynamic halt-polling


It seems to be a poor interaction of the halt polling interval vs the timer
ticks on win10.  You can pick a different polling interval with the kvm
module option halt_poll_ns.  The default is 500000.  It seemed that setting
this to 400000 or lower resolves the issue.  You can do this via a modprobe
entry, 'options kvm halt_poll_ns=400000' or on the kernel command line with
kvm.halt_poll_ns=400000.  You can also change it dynamically via 'echo
400000 > /sys/module/kvm/parameters/halt_poll_ns'
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/vfio-users/attachments/20160403/47dc9de7/attachment.htm>

More information about the vfio-users mailing list