Re: [EXT] Re: [PATCH 1/1] net: fec: add initial XDP support

Ilias Apalodimas
2022-10-07T08:09:11Z

Hi Jesper,

On Thu, 6 Oct 2022 at 11:37, Jesper Dangaard Brouer <jbrouer@redhat.com> wrote:
>
>
>
> On 05/10/2022 14.40, Shenwei Wang wrote:
> > Hi Jesper,
> >
> > Here is the summary of "xdp_rxq_info" testing.
> >
> > skb_mark_for_recycle page_pool_release_page
> >
> > Native SKB-Mode Native SKB-Mode
> > XDP_DROP 460K 220K 460K 102K
> > XDP_PASS 80K 113K 60K 62K
> >
>
> It is very pleasing to see the *huge* performance benefit that page_pool
> provide when recycling pages for SKBs (via skb_mark_for_recycle).
> I did expect a performance boost, but not around a x2 performance boost.

Indeed that's a pleasant surprise. Keep in mind that if we convert
more driver we
can also get rid of copy_break code sprinkled around in drivers.

Thanks
/Ilias
>
> I guess this platform have a larger overhead for DMA-mapping and
> page-allocation.
>
> IMHO it would be valuable to include this result as part of the patch
> description when you post the XDP patch again.
>
> Only strange result is XDP_PASS 'Native' is slower that 'SKB-mode'. I
> cannot explain why, as XDP_PASS essentially does nothing and just follow
> normal driver code to netstack.
>
> Thanks a lot for doing these tests.
> --Jesper
>
> > The following are the testing log.
> >
> > Thanks,
> > Shenwei
> >
> > ### skb_mark_for_recycle solution ###
> >
> > ./xdp_rxq_info --dev eth0 --act XDP_DROP --read
> >
> > Running XDP on dev:eth0 (ifindex:2) action:XDP_DROP options:read
> > XDP stats CPU pps issue-pps
> > XDP-RX CPU 0 466,553 0
> > XDP-RX CPU total 466,553
> >
> > ./xdp_rxq_info -S --dev eth0 --act XDP_DROP --read
> >
> > Running XDP on dev:eth0 (ifindex:2) action:XDP_DROP options:read
> > XDP stats CPU pps issue-pps
> > XDP-RX CPU 0 226,272 0
> > XDP-RX CPU total 226,272
> >
> > ./xdp_rxq_info --dev eth0 --act XDP_PASS --read
> >
> > Running XDP on dev:eth0 (ifindex:2) action:XDP_PASS options:read
> > XDP stats CPU pps issue-pps
> > XDP-RX CPU 0 80,518 0
> > XDP-RX CPU total 80,518
> >
> > ./xdp_rxq_info -S --dev eth0 --act XDP_PASS --read
> >
> > Running XDP on dev:eth0 (ifindex:2) action:XDP_PASS options:read
> > XDP stats CPU pps issue-pps
> > XDP-RX CPU 0 113,681 0
> > XDP-RX CPU total 113,681
> >
> >
> > ### page_pool_release_page solution ###
> >
> > ./xdp_rxq_info --dev eth0 --act XDP_DROP --read
> >
> > Running XDP on dev:eth0 (ifindex:2) action:XDP_DROP options:read
> > XDP stats CPU pps issue-pps
> > XDP-RX CPU 0 463,145 0
> > XDP-RX CPU total 463,145
> >
> > ./xdp_rxq_info -S --dev eth0 --act XDP_DROP --read
> >
> > Running XDP on dev:eth0 (ifindex:2) action:XDP_DROP options:read
> > XDP stats CPU pps issue-pps
> > XDP-RX CPU 0 104,443 0
> > XDP-RX CPU total 104,443
> >
> > ./xdp_rxq_info --dev eth0 --act XDP_PASS --read
> >
> > Running XDP on dev:eth0 (ifindex:2) action:XDP_PASS options:read
> > XDP stats CPU pps issue-pps
> > XDP-RX CPU 0 60,539 0
> > XDP-RX CPU total 60,539
> >
> > ./xdp_rxq_info -S --dev eth0 --act XDP_PASS --read
> >
> > Running XDP on dev:eth0 (ifindex:2) action:XDP_PASS options:read
> > XDP stats CPU pps issue-pps
> > XDP-RX CPU 0 62,566 0
> > XDP-RX CPU total 62,566
> >
> >> -----Original Message-----
> >> From: Shenwei Wang
> >> Sent: Tuesday, October 4, 2022 8:34 AM
> >> To: Jesper Dangaard Brouer <jbrouer@redhat.com>; Andrew Lunn
> >> <andrew@lunn.ch>
> >> Cc: brouer@redhat.com; David S. Miller <davem@davemloft.net>; Eric Dumazet
> >> <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo Abeni
> >> <pabeni@redhat.com>; Alexei Starovoitov <ast@kernel.org>; Daniel Borkmann
> >> <daniel@iogearbox.net>; Jesper Dangaard Brouer <hawk@kernel.org>; John
> >> Fastabend <john.fastabend@gmail.com>; netdev@vger.kernel.org; linux-
> >> kernel@vger.kernel.org; imx@lists.linux.dev; Magnus Karlsson
> >> <magnus.karlsson@gmail.com>; Björn Töpel <bjorn@kernel.org>; Ilias
> >> Apalodimas <ilias.apalodimas@linaro.org>
> >> Subject: RE: [EXT] Re: [PATCH 1/1] net: fec: add initial XDP support
> >>
> >>
> >>
> >>> -----Original Message-----
> >>> From: Shenwei Wang
> >>> Sent: Tuesday, October 4, 2022 8:13 AM
> >>> To: Jesper Dangaard Brouer <jbrouer@redhat.com>; Andrew Lunn
> >> ...
> >>> I haven't tested xdp_rxq_info yet, and will have a try sometime later today.
> >>> However, for the XDP_DROP test, I did try xdp2 test case, and the
> >>> testing result looks reasonable. The performance of Native mode is
> >>> much higher than skb- mode.
> >>>
> >>> # xdp2 eth0
> >>> proto 0: 475362 pkt/s
> >>>
> >>> # xdp2 -S eth0 (page_pool_release_page solution)
> >>> proto 17: 71999 pkt/s
> >>>
> >>> # xdp2 -S eth0 (skb_mark_for_recycle solution)
> >>> proto 17: 72228 pkt/s
> >>>
> >>
> >> Correction for xdp2 -S eth0 (skb_mark_for_recycle solution)
> >> proto 0: 0 pkt/s
> >> proto 17: 122473 pkt/s
> >>
> >> Thanks,
> >> Shenwei
> >
>