LPC Traffic Shaping w/ BPF Talk - percpu followup

[Dennis Zhou]

Hi Eddie, Vlad, and Willem,

A few people mentioned to me that you guys were experiencing issues with
the percpu memory allocator. I saw the talk slides mention the
following two bullets:

1) allocation pattern makes the per cpu allocator reach a highly
   fragmented state
2) sometimes takes a long time (up to 12s) to create the PERCPU_HASH
   maps at startup

Could you guys elaborate a little more about the above? Some things
that would help: kernel version, cpu info, and a reproducer if possible?

Also, I did some work last summer to make percpu allocation more
efficient, which went into the 4.14 kernel. Just to be sure, is that a
part of the kernel you guys are running?

Thanks,
Dennis