Messages in this thread | | | From | Jesper Dangaard Brouer <> | Date | Fri, 3 Mar 2023 11:39:06 +0100 | Subject | Re: [PATCH bpf-next v1 0/2] xdp: recycle Page Pool backed skbs built from XDP frames |
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On 01/03/2023 17.03, Alexander Lobakin wrote: > Yeah, I still remember that "Who needs cpumap nowadays" (c), but anyway. > > __xdp_build_skb_from_frame() missed the moment when the networking stack > became able to recycle skb pages backed by a Page Pool. This was making ^^^^^^^^^ When talking about page_pool, can we write "page_pool" instead of capitalized "Page Pool", please. I looked through the git log, and here we all used "page_pool".
> e.g. cpumap redirect even less effective than simple %XDP_PASS. veth was > also affected in some scenarios.
Thanks for working on closing this gap :-)
> A lot of drivers use skb_mark_for_recycle() already, it's been almost > two years and seems like there are no issues in using it in the generic > code too. {__,}xdp_release_frame() can be then removed as it losts its > last user. > Page Pool becomes then zero-alloc (or almost) in the abovementioned > cases, too. Other memory type models (who needs them at this point) > have no changes. > > Some numbers on 1 Xeon Platinum core bombed with 27 Mpps of 64-byte > IPv6 UDP:
What NIC driver?
> > Plain %XDP_PASS on baseline, Page Pool driver: > > src cpu Rx drops dst cpu Rx > 2.1 Mpps N/A 2.1 Mpps > > cpumap redirect (w/o leaving its node) on baseline: > > 6.8 Mpps 5.0 Mpps 1.8 Mpps > > cpumap redirect with skb PP recycling: > > 7.9 Mpps 5.7 Mpps 2.2 Mpps +22% >
It is of cause awesome, that cpumap SKBs are faster than normal SKB path. I do wonder where the +22% number comes from?
> Alexander Lobakin (2): > xdp: recycle Page Pool backed skbs built from XDP frames > xdp: remove unused {__,}xdp_release_frame() > > include/net/xdp.h | 29 ----------------------------- > net/core/xdp.c | 19 ++----------------- > 2 files changed, 2 insertions(+), 46 deletions(-) >
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