[ovs-dev] [patch v2 5/5] conntrack: Optimize recirculations.

[Aaron Conole]

Darrell Ball <dlu998 at gmail.com> writes:

> In most cases, recirculations through conntrack can be much less costly.
>
> Signed-off-by: Darrell Ball <dlu998 at gmail.com>
> ---
>  lib/conntrack.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++---
>  lib/packets.h   |  4 ++++
>  2 files changed, 51 insertions(+), 3 deletions(-)
>
> diff --git a/lib/conntrack.c b/lib/conntrack.c
> index 9d10b14..f9c4d90 100644
> --- a/lib/conntrack.c
> +++ b/lib/conntrack.c
> @@ -51,6 +51,7 @@ struct conn_lookup_ctx {
>      uint32_t hash;
>      bool reply;
>      bool icmp_related;
> +    bool nat;

Is this already available via testing for conn->nat_info?  Maybe I'm
misunderstanding something.  Probably I am.

>  };
>  
>  enum ftp_ctl_pkt {
> @@ -954,7 +955,7 @@ conn_not_found(struct dp_packet *pkt, struct conn_lookup_ctx *ctx,
>              }
>              nc->ext_nat->nat_conn = nat_conn;
>              nat_packet(pkt, nc, ctx->icmp_related);
> -
> +            ctx->nat = true;
>              nat_conn->key = nc->rev_key;
>              nat_conn->rev_key = nc->key;
>              nat_conn->conn_type = CT_CONN_TYPE_UN_NAT;
> @@ -1193,6 +1194,7 @@ process_one(struct dp_packet *pkt, struct conn_lookup_ctx *ctx, uint16_t zone,
>          }
>          if (nat_action_info && !create_new_conn) {
>              handle_nat(pkt, conn, zone, ctx->reply, ctx->icmp_related);
> +            ctx->nat = true;
>          }
>      } else if (check_orig_tuple(pkt, ctx, now, &conn, nat_action_info)) {
>          create_new_conn = conn_update_state(pkt, ctx, conn, now);
> @@ -1237,6 +1239,39 @@ process_one(struct dp_packet *pkt, struct conn_lookup_ctx *ctx, uint16_t zone,
>      }
>  
>      handle_alg_ctl(ctx, pkt, ct_alg_ctl, conn, now, !!nat_action_info);
> +
> +    if (!ctx->nat && ct_alg_ctl == CT_ALG_CTL_NONE) {
> +        pkt->md.conn = conn;
> +        pkt->md.reply = ctx->reply;
> +        pkt->md.icmp_related = ctx->icmp_related;
> +    } else {
> +        pkt->md.conn = NULL;
> +    }
> +}
> +
> +static inline void
> +process_one_fast(struct dp_packet *pkt, uint16_t zone,
> +                 const uint32_t *setmark,
> +                 const struct ovs_key_ct_labels *setlabel,
> +                 const struct nat_action_info_t *nat_action_info,
> +                 struct conn *conn)
> +{
> +    if (nat_action_info) {
> +        handle_nat(pkt, conn, zone, pkt->md.reply, pkt->md.icmp_related);
> +        pkt->md.conn = NULL;
> +    }
> +
> +    pkt->md.ct_zone = zone;
> +    pkt->md.ct_mark = conn->mark;
> +    pkt->md.ct_label = conn->label;
> +
> +    if (setmark) {
> +        set_mark(pkt, conn, setmark[0], setmark[1]);
> +    }
> +
> +    if (setlabel) {
> +        set_label(pkt, conn, &setlabel[0], &setlabel[1]);
> +    }
>  }
>  
>  /* Sends the packets in '*pkt_batch' through the connection tracker 'ct'.  All
> @@ -1260,8 +1295,16 @@ conntrack_execute(struct dp_packet_batch *pkt_batch, ovs_be16 dl_type,
>      struct conn_lookup_ctx ctx;
>  
>      DP_PACKET_BATCH_FOR_EACH (i, packet, pkt_batch) {
> -        if (packet->md.ct_state == CS_INVALID
> -            || !conn_key_extract(packet, dl_type, &ctx, zone)) {
> +        struct conn *conn = packet->md.conn;
> +        if (OVS_UNLIKELY(packet->md.ct_state == CS_INVALID)) {
> +            write_ct_md(packet, zone, NULL, NULL, NULL);
> +                continue;
> +        } else if (conn && !force && !commit && conn->key.zone == zone) {
> +            process_one_fast(packet, zone, setmark, setlabel, nat_action_info,
> +                             packet->md.conn);
> +            continue;
> +        } else if (OVS_UNLIKELY(!conn_key_extract(packet, dl_type, &ctx,
> +                                zone))) {
>              packet->md.ct_state = CS_INVALID;
>              write_ct_md(packet, zone, NULL, NULL, NULL);
>              continue;
> @@ -1279,6 +1322,7 @@ conntrack_clear(struct dp_packet *packet)
>      /* According to pkt_metadata_init(), ct_state == 0 is enough to make all of
>       * the conntrack fields invalid. */
>      packet->md.ct_state = 0;
> +    packet->md.conn = NULL;
>  }
>  
>  static void
> diff --git a/lib/packets.h b/lib/packets.h
> index 09a0ac3..a88d1ad 100644
> --- a/lib/packets.h
> +++ b/lib/packets.h
> @@ -108,6 +108,9 @@ PADDED_MEMBERS_CACHELINE_MARKER(CACHE_LINE_SIZE, cacheline0,
>      uint32_t ct_mark;           /* Connection mark. */
>      ovs_u128 ct_label;          /* Connection label. */
>      union flow_in_port in_port; /* Input port. */
> +    void *conn;
> +    bool reply;
> +    bool icmp_related;
>  );
>  
>  PADDED_MEMBERS_CACHELINE_MARKER(CACHE_LINE_SIZE, cacheline1,
> @@ -157,6 +160,7 @@ pkt_metadata_init(struct pkt_metadata *md, odp_port_t port)
>      md->tunnel.ip_dst = 0;
>      md->tunnel.ipv6_dst = in6addr_any;
>      md->in_port.odp_port = port;
> +    md->conn = NULL;
>  }
>  
>  /* This function prefetches the cachelines touched by pkt_metadata_init()