Re: [PATCHv4 bpf-next 0/2] xdp: add dev map multicast support

On Wed, 10 Jun 2020 10:35:08 +0800
Hangbin Liu [off-list ref] wrote:

On Tue, Jun 09, 2020 at 10:31:19PM +0200, Toke Høiland-Jørgensen wrote:

quoted

quoted

Oh, sorry for the typo, the numbers make me crazy, it should be only
ingress i40e, egress veth. Here is the right description:

Kernel 5.7 + my patch(ingress i40e, egress i40e)
xdp_redirect_map:
  generic mode: 1.9M PPS
  driver mode: 10.2M PPS

xdp_redirect_map_multi:
  generic mode: 1.58M PPS
  driver mode: 7.16M PPS

Kernel 5.7 + my patch(ingress i40e, egress veth(No XDP on peer))
xdp_redirect_map:
  generic mode: 2.2M PPS
  driver mode: 14.2M PPS  

A few messages up-thread you were getting 4.15M PPS in this case - what
changed? It's inconsistencies like these that make me suspicious of the
whole set of results :/  

I got the number after a reboot, not sure what happened.
And I also feel surprised... But the result shows the number, so I have
to put it here.

quoted

Are you getting these numbers from ethtool_stats.pl or from the XDP
program? What counter are you looking at, exactly?  

For bridge testing I use ethtool_stats.pl. For later xdp_redirect_map
and xdp_redirect_map_multi testing, I checked that ethtool_stats.pl and
XDP program shows the same number. When run ethtool_stats.pl the number
will go a little bit slower. So at the end I use the xdp program's number.

You cannot trust the xdp program's number, because it just counts all
RX-packets, and don't take into account if the packets are getting
dropped.  We really want to verify (e.g. with ethtool_stats.pl) that
the packets were successfully transmitted.

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer