On Fri, Jul 31, 2015 at 03:10:24PM +0100, Ben Gray wrote:
Hi,
I've a question on whether it's 'safe' to change the socket type used in virNetxxx calls from AF_PACKET to AF_LOCAL ?
The reason I ask is that we're using libvirt-lxc with a couple of bridge interfaces, and we've found that the socket close call on AF_PACKET type sockets takes between 40ms and 60ms. For our container config there is roughly 12 close calls on AF_PACKET sockets, delaying the start-up of the LXC container by around 450ms.
So a simple fix to speed up our container start-up is to just switch from AF_PACKET to AF_LOCAL sockets. Hence my question on whether we can safely do this, or is there some reason why AF_PACKET was chosen ?
AFAIK, there's no particular reason why we chose AF_PACKET - we were probably just copying code somewhere else. Looking at the kernel code it seems the various ioctls() we do are accepted on any type of socket family. So if AF_LOCAL works, I don't see a reason not to change it. We should probably test old distro like RHEL5 to be sure there's no historical reason for it though. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|