Comment by VioletVillain

For the posterity, I've managed to make Blitzping much faster: on the ARMv8-A device, it went from ~10.5 MiB/s to ~120 MiB/s. Instead of sendto(), I used a single connect() call to bind the raw socket to its destination, and then I used writev() calls to "queue" many packets for sending. Internally, writev() [and its other counterpart, sendmmsg()] still uses the same for-loop'ing mechanism to iterate through its queue, but said loop would exist in kernelspace, requiring less userspace->kernelspace syscalls to accomplish the same goal.