[dpdk-dev] Configuring NIC Tx arbiters in VMDK off, DCB off mode

[dpdk-dev] Configuring NIC Tx arbiters in VMDK off, DCB off mode

[Lavanya Jose]

Hi everyone,

I found a snippet
<https://github.com/snabbco/snabb/blob/master/src/apps/intel/intel10g.lua#L983>
of
code from a userspace driver that lets you configure weights for the
hardware NIC tx queues by configuring the RTTDT1C register in Intel 82599.
It looks like this is typically used for rate limiting VM traffic, with the
NIC in VMDQ mode. I was wondering whether I can do this without setting up
the NIC in VMDQ or DCB mode?

I am directly enqueuing CustomProto/UDP/IP/Ethernet packets from a single
process (two threads) on to specific hardware queues (without an
intermediate DPDK QOS/ Hierarchical Scheduler layer) and updating the
hardware queue rates, so the priority/ hardware rate limiting are the only
features I need (not VMDQ, DCB). Can I go about just changing the weights
as in the code above with VMDQ and DCB turned off?

Some initial experiments I did suggest that setting just the RTTDT1C
register for queues doesn't make any difference to the relative throughput
of the queues..

Thanks,
Lavanya