[libvirt] libvirtd cpu usage

[Daniel P. Berrange]

On Thu, May 15, 2008 at 11:47:44AM +0200, Thomas Mueller wrote:
> hi there
> 
> i'm playing on debian lenny with kvm-66/libvirt-0.4.2 .
> 
> if i run top, i see libvirtd is top cpu consumer. if i connect with 
> strace to libvirtd, i see a thousand times this message:
> 
> poll([{fd=3, events=POLLIN}, {fd=6, events=POLLIN|POLLERR|POLLHUP}, 
> {fd=7, events=POLLIN|POLLERR|POLLHUP}, {fd=8, events=POLLIN}, {fd=13, 
> events=POLLIN|POLLERR|POLLHUP, revents=POLLHUP}, {fd=15, 
> events=POLLIN|POLLERR|POLLHUP, revents=POLLHUP}, {fd=17, 
> events=POLLIN|POLLERR|POLLHUP}, {fd=19, events=POLLIN|POLLERR|POLLHUP}], 
> 8, -1) = 2

So this is saying 2 of file descriptors have hit 'end of file' condition
and for some bizarre reason libvirt is not cleaning them up. What do you
do to cause trigger the high CPU usage ?  Does it occurr the moment you
start libvirtd ? Or only when you start a VM ? Or only when you shutdown
a VM ? Or something else altogether...

The output of 'lsof -p'  on the libvirtd process might be helpful. You
might also try running  with --verbose and LIBVIRT_DEBUG=1 envirnoment
variable set and capturing the output

Regards,
Dan.
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