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

[Ilias Apalodimas]

Hi Jesper,

On Thu, 6 Oct 2022 at 11:37, Jesper Dangaard Brouer <jbrouer@xxxxxxxxxx> 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@xxxxxxxxxx>; Andrew Lunn
> >> <andrew@xxxxxxx>
> >> Cc: brouer@xxxxxxxxxx; David S. Miller <davem@xxxxxxxxxxxxx>; Eric Dumazet
> >> <edumazet@xxxxxxxxxx>; Jakub Kicinski <kuba@xxxxxxxxxx>; Paolo Abeni
> >> <pabeni@xxxxxxxxxx>; Alexei Starovoitov <ast@xxxxxxxxxx>; Daniel Borkmann
> >> <daniel@xxxxxxxxxxxxx>; Jesper Dangaard Brouer <hawk@xxxxxxxxxx>; John
> >> Fastabend <john.fastabend@xxxxxxxxx>; netdev@xxxxxxxxxxxxxxx; linux-
> >> kernel@xxxxxxxxxxxxxxx; imx@xxxxxxxxxxxxxxx; Magnus Karlsson
> >> <magnus.karlsson@xxxxxxxxx>; Björn Töpel <bjorn@xxxxxxxxxx>; Ilias
> >> Apalodimas <ilias.apalodimas@xxxxxxxxxx>
> >> 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@xxxxxxxxxx>; 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
> >
>