increase backlog and txqueulen for high-performance interfaces

[Vladimir Kuklin]

For some bridges and interfaces, Fuel configures txqueulen=0, which impacts CPU load badly.

The net.core.netdev_max_backlog should be also adjusted in order to increase networking performance. Current settings of net.core.netdev_max_backlog=1000, this is to small for 10Gb/s interfaces. More info about netdev_max_backlog, see at http://www.tldp.org/HOWTO/KernelAnalysis-HOWTO-5.html (/proc/sys/net/core section of document)

[Bogdan Dobrelya (bogdando)]

Cannot be fixed for the 6.0.x as the l23network refactoring feature cannot be backported

[Bogdan Dobrelya (bogdando)]

Related bug for packet steering https://bugs.launchpad.net/fuel/+bug/1456587

[Vladimir Kuklin (vkuklin)]

I am marking this bug as won't fix until we get additional verification that these options need to be applied

[Vladimir Kuklin (vkuklin)]

related fix https://review.openstack.org/#/c/184312/

[Aleksandr Didenko (adidenko)]

Moved to 8.0 with approval from dev and QA

[Dmitry Pyzhov (dpyzhov)]

We passed SCF for 9.0. Moving the medium priority bug to 10.0 release.