tree 7f9f19040af3ec4d73d0b21878886ae1a84afc67
parent f320460b9489d80355821829069fdefa6c698cb4
author Magnus Karlsson <magnus.karlsson@intel.com> 1605525165 +0100
committer Daniel Borkmann <daniel@iogearbox.net> 1605647260 +0100

xsk: Introduce padding between more ring pointers

Introduce one cache line worth of padding between the consumer pointer
and the flags field as well as between the flags field and the start
of the descriptors in all the lockless rings. This so that the x86 HW
adjacency prefetcher will not prefetch the adjacent pointer/field when
only one pointer/field is going to be used. This improves throughput
performance for the l2fwd sample app with 1% on my machine with HW
prefetching turned on in the BIOS.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/1605525167-14450-4-git-send-email-magnus.karlsson@gmail.com