I struggle to understand the concept of how RSS connects to PFRING cluster load balancing.
Here is my current understanding. When RSS is configured NIC calculates packet hashes and places them in a RSS queues. On the other side PFRING kernel module takes packet from NIC and places them in the ring.
How does those two come together? Does PFRING takes packets from RSS queue and puts them in ring?
This is what I was able to discover.
As I understand it, the NIC is instructed on the destination where to copy the packet. Once this is done we have the packet copied by the NIC to the PF_RING ring (1-copy) and an interrupt is thrown, bypassing the kernel (no 2-copy). The ring queue is mapped per RSS during NIC driver initialization.
In 0-copy mode we bypass the PF_RING ring and access the NIC memory directly