Re: [PATCH v2 net-next 0/6] skbuff: micro-optimize flow dissection

From: Alexander Lobakin
Date: Sat Mar 13 2021 - 08:31:25 EST


From: Alexander Lobakin <alobakin@xxxxx>
Date: Sat, 13 Mar 2021 11:37:03 +0000

> This little number makes all of the flow dissection functions take
> raw input data pointer as const (1-5) and shuffles the branches in
> __skb_header_pointer() according to their hit probability.
>
> The result is +20 Mbps per flow/core with one Flow Dissector pass
> per packet. This affects RPS (with software hashing), drivers that
> use eth_get_headlen() on their Rx path and so on.
>
> Since v1 [0]:
> - rebase on top of the latest net-next. This was super-weird, but
> I double-checked that the series applies with no conflicts, and
> then on Patchwork it didn't;

Still failing on Patchwork. I rebased it ten thousand times, rebuilt
the patches manually, tried previous stable Git version and the
latest CVS snapshot, and always got the same series that successfully
applies to next-next.
Can you please take a look?

> - no other changes.
>
> [0] https://lore.kernel.org/netdev/20210312194538.337504-1-alobakin@xxxxx
>
> Alexander Lobakin (6):
> flow_dissector: constify bpf_flow_dissector's data pointers
> skbuff: make __skb_header_pointer()'s data argument const
> flow_dissector: constify raw input @data argument
> linux/etherdevice.h: misc trailing whitespace cleanup
> ethernet: constify eth_get_headlen()'s @data argument
> skbuff: micro-optimize {,__}skb_header_pointer()
>
> include/linux/etherdevice.h | 4 ++--
> include/linux/skbuff.h | 26 +++++++++++------------
> include/net/flow_dissector.h | 6 +++---
> net/core/flow_dissector.c | 41 +++++++++++++++++++-----------------
> net/ethernet/eth.c | 2 +-
> 5 files changed, 40 insertions(+), 39 deletions(-)
>
> --
> 2.30.2

Thanks,
Al