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

[Jesper Dangaard Brouer]

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.

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