Formal RingBuffer 3: Getting Low and Getting Results

build_packet.zig

pub fn buildPacket() []const u8 {
    // Define the packet components
    const dest_mac: [6]u8 = [_]u8{ 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF }; // Destination MAC
    const src_mac: [6]u8 = [_]u8{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; // Source MAC
    const ethertype: [2]u8 = [_]u8{ 0x08, 0x00 }; // EtherType (IPv4)
    const payload: [46]u8 = [_]u8{0} ** 46; // Payload (46 bytes of zeroes)

    // Combine all components into a single array
    const packet: [60]u8 = [_]u8{
        // Destination MAC
        dest_mac[0],  dest_mac[1],  dest_mac[2], dest_mac[3], dest_mac[4], dest_mac[5],
        // Source MAC
        src_mac[0],   src_mac[1],   src_mac[2],  src_mac[3],  src_mac[4],  src_mac[5],
        // EtherType
        ethertype[0], ethertype[1],
        // Payload
        payload[0],  payload[1],  payload[2],  payload[3],
        payload[4],   payload[5],   payload[6],  payload[7],  payload[8],  payload[9],
        payload[10],  payload[11],  payload[12], payload[13], payload[14], payload[15],
        payload[16],  payload[17],  payload[18], payload[19], payload[20], payload[21],
        payload[22],  payload[23],  payload[24], payload[25], payload[26], payload[27],
        payload[28],  payload[29],  payload[30], payload[31], payload[32], payload[33],
        payload[34],  payload[35],  payload[36], payload[37], payload[38], payload[39],
        payload[40],  payload[41],  payload[42], payload[43], payload[44], payload[45],
    };

    // Return as a slice
    return packet[0..];
}

The Python speeds are as follows for tx.py:

870.232124 main_thread [2781] 17.326 Mpps (17.335 Mpkts 8.317 Gbps in 1000479 usec) 256.34 avg_batch 1 min_space
871.233117 main_thread [2781] 19.112 Mpps (19.131 Mpkts 9.174 Gbps in 1000994 usec) 256.22 avg_batch 1 min_space
872.234124 main_thread [2781] 17.408 Mpps (17.425 Mpkts 8.356 Gbps in 1001007 usec) 256.14 avg_batch 256 min_space
873.235122 main_thread [2781] 18.698 Mpps (18.717 Mpkts 8.975 Gbps in 1000998 usec) 256.34 avg_batch 1 min_space
874.236123 main_thread [2781] 19.919 Mpps (19.939 Mpkts 9.561 Gbps in 1001001 usec) 256.15 avg_batch 1 min_space
875.237122 main_thread [2781] 18.584 Mpps (18.603 Mpkts 8.921 Gbps in 1000999 usec) 256.10 avg_batch 1 min_space
876.238111 main_thread [2781] 19.494 Mpps (19.513 Mpkts 9.357 Gbps in 1000989 usec) 256.06 avg_batch 256 min_space

And now the new and improved Zig speed:

956.379630 main_thread [2781] 24.087 Mpps (24.112 Mpkts 11.562 Gbps in 1001033 usec) 256.05 avg_batch 0 min_space
957.380678 main_thread [2781] 24.205 Mpps (24.230 Mpkts 11.618 Gbps in 1001048 usec) 256.03 avg_batch 512 min_space
958.381724 main_thread [2781] 24.406 Mpps (24.431 Mpkts 11.715 Gbps in 1001047 usec) 256.02 avg_batch 512 min_space
959.382651 main_thread [2781] 24.374 Mpps (24.396 Mpkts 11.699 Gbps in 1000927 usec) 256.03 avg_batch 1 min_space
960.383717 main_thread [2781] 23.921 Mpps (23.946 Mpkts 11.482 Gbps in 1001066 usec) 256.04 avg_batch 256 min_space
961.384121 main_thread [2781] 24.063 Mpps (24.073 Mpkts 11.550 Gbps in 1000403 usec) 256.02 avg_batch 512 min_space
962.385148 main_thread [2781] 24.095 Mpps (24.120 Mpkts 11.566 Gbps in 1001027 usec) 256.01 avg_batch 256 min_space
963.386189 main_thread [2781] 22.208 Mpps (22.231 Mpkts 10.660 Gbps in 1001042 usec) 256.02 avg_batch 256 min_space
964.387235 main_thread [2781] 21.936 Mpps (21.959 Mpkts 10.529 Gbps in 1001046 usec) 256.02 avg_batch 1 min_space
965.388283 main_thread [2781] 23.325 Mpps (23.349 Mpkts 11.196 Gbps in 1001047 usec) 256.02 avg_batch 256 min_space
966.389328 main_thread [2781] 24.206 Mpps (24.232 Mpkts 11.619 Gbps in 1001046 usec) 256.02 avg_batch 1 min_space

As you can see they are nearly the same because they are, for once, actually doing the same thing! Imagine that. After getting all excited I realized how seriously bad it was that I was sending these packets with a length of 60 and somehow saturating the connection. Basically, that's just not possible if everything is exactly the same. I finally do get packets on the other end of the vale switch using onepacket.py as well:

Waiting for a packet to come
Received a packet with len 60
ffffffffffff000000000000080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
Waiting for a packet to come
Received a packet with len 60
ffffffffffff000000000000080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
Waiting for a packet to come
Received a packet with len 60
ffffffffffff000000000000080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
Waiting for a packet to come
Received a packet with len 60
ffffffffffff000000000000080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

The number one primary thing to remember is that netmap does not make your network go faster! Despite this many applications using it are based around doing things fast- go figure.