[$] Batch processing of network packets
It has been understood for years that kernel performance can be improved by
doing things in batches. Whether the task is freeing memory pages,
initializing data structures, or performing I/O, things go faster if the
work is done on many objects at once; many kernel subsystems have been
reworked to take advantage of the efficiency of batching. It turns out,
though, that there was
a piece of relatively low-hanging fruit at the core of the kernel's network
stack. The 4.19 kernel will feature some work increasing the batching of
packet processing, resulting in some impressive performance improvements.