Subject: Re: [PATCH net-next v3 0/5] TC: refactor act_mirred packets re-injection

From: Jiri Pirko <[email-masked]>
Date: Wed, 25 Jul 2018 13:53:45 +0200

Tue, Jul 24, 2018 at 10:06:38PM CEST, [email-masked] wrote:
>This series is aimed at improving the act_mirred redirect performances.
>Such action is used by OVS to represent TC S/W flows, and it's current largest
>bottle-neck is the need for a skb_clone() for each packet.
>
>The first 3 patches introduce some cleanup and safeguards to allow extending 
>tca_result - we will use it to store RCU protected redirect information - and
>introduce a clear separation between user-space accessible tcfa_action
>value and internal values accessible only by the kernel.
>Then a new tcfa_action value is introduced: TC_ACT_REINJECT, similar to
>TC_ACT_REDIRECT, but preserving the mirred semantic. Such value is not
>accessible from user-space.
>The last patch exploits the newly introduced infrastructure in the act_mirred
>action, to avoid a skb_clone, when possible.
>
>Overall this the above gives a ~10% performance improvement in forwarding tput,
>when using the TC S/W datapath.
>
>v1 -> v2:
> - preserve the rcu lock in act_bpf
> - add and use a new action value to reinject the packets, preserving the mirred
>   semantic
>
>v2 -> v3:
> - renamed to new action as TC_ACT_REINJECT
> - TC_ACT_REINJECT is not exposed to user-space
>
>Paolo Abeni (5):
>  tc/act: user space can't use TC_ACT_REDIRECT directly
>  net/sched: user-space can't set unknown tcfa_action values
>  tc/act: remove unneeded RCU lock in action callback
>  net/tc: introduce TC_ACT_REINJECT.
>  act_mirred: use TC_ACT_REINJECT when possible

Could you please send the userspace iproute2 patch and list some
examples of usage along with the next patchset version?

Also, I would like you to do selftest script to test this and have it as
a part of this patchset.

Thanks!

>
> include/net/act_api.h        |  2 +-
> include/net/pkt_cls.h        |  3 +++
> include/net/sch_generic.h    | 21 ++++++++++++++++++++
> include/uapi/linux/pkt_cls.h |  6 ++++--
> net/core/dev.c               |  6 +++++-
> net/sched/act_api.c          | 15 +++++++++++++-
> net/sched/act_csum.c         | 12 +++---------
> net/sched/act_ife.c          |  5 +----
> net/sched/act_mirred.c       | 38 ++++++++++++++++++++++++------------
> net/sched/act_sample.c       |  4 +---
> net/sched/act_skbedit.c      | 10 +++-------
> net/sched/act_skbmod.c       | 21 +++++++++-----------
> net/sched/act_tunnel_key.c   |  6 +-----
> net/sched/act_vlan.c         | 19 +++++++-----------
> 14 files changed, 98 insertions(+), 70 deletions(-)
>
>-- 
>2.17.1
>