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 2 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 values 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 v3 -> v4: - dropped the TC_ACT_REDIRECT patch - report failure via extack, too - rename the new action as TC_ACT_REINSERT - skip clone only if the control action don't touch tcf_result Paolo Abeni (4): 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_REINSERT. act_mirred: use TC_ACT_REINSERT when possible 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 | 17 +++++++++++ net/sched/act_csum.c | 12 ++------ net/sched/act_ife.c | 5 +-- net/sched/act_mirred.c | 59 +++++++++++++++++++++++++++--------- 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, 121 insertions(+), 70 deletions(-) -- 2.17.1
