>> 2. How is the logic aware of RSS and RFS? >> >> With TCP sockets, the driver knows the specific ring it need to poll so >> this should be mapped and provide the best latency. > > > This code is blissfully oblivious of RFS and RSS, it only assumes that the > packets for a socket are likely to continue to come on the same queue. > The code is designed to be correct even if you get your data on the wrong > queue. (your performance will suffer but no more than that.) >
For low latency, you don't want to have to wait for the IPI that RPS sets to redirect packets to another CPU. However, this feature works extremely well with hardware flow steering (nfc/ntuple) and accelerated RFS, where the device will enqueue directly on an rxqueue owned exclusively by the destination cpu (if configured correctly). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/