Packet loss > 900 kPPS

[krjoshi]

Packet loss when using VFd through a switch has been reported. No packet loss is seen when NIC is connected back to back to another NIC.

Root cause is under investigation.

[krjoshi]

Symptoms:

• Packets being dropped on RX side by VFd
• Problem does not happen if other side is a back to back connection to another VFd process.
• Problem does not happen with ixgbe driver.

Suspect MTU > 1500 bug as the root cause. Will test with MTU patch to see if packet loss is resolved.

[krjoshi]

Issue was diagnosed to be the result of the NIC responding to flow control messages from the switch.

Hard setting flow control off irrespective of switch setting improved packet loss substantially. Testing underway to verify if this solves the problem entirely.