[libvirt] libvirtd cpu usage

[Daniel P. Berrange]

On Thu, May 15, 2008 at 05:03:37PM +0200, Thomas Mueller wrote:
> hi daniel
> 
> 
> >>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
> 
> hmm.. ok, i can't reproduce it anymore. :/ but i found a second libvirtd 
> process in defunct state. maybe this was the cause for this "bizzare 
> reason libvirt not cleaning them up".
> 
> after rebooting i tested again and libvirtd was not consuming all of the 
> cpu...

Well if it hits you again let us know, because it sounds like there's a
wierd edge case bug hiding in there somewhere...

Dan.
-- 
|: Red Hat, Engineering, Boston   -o-   http://people.redhat.com/berrange/ :|
|: http://libvirt.org  -o-  http://virt-manager.org  -o-  http://ovirt.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: GnuPG: 7D3B9505  -o-  F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|