• Daniel Borkmann's avatar
    net: use jump label patching for ingress qdisc in __netif_receive_skb_core · 4577139b
    Daniel Borkmann authored
    Even if we make use of classifier and actions from the egress
    path, we're going into handle_ing() executing additional code
    on a per-packet cost for ingress qdisc, just to realize that
    nothing is attached on ingress.
    
    Instead, this can just be blinded out as a no-op entirely with
    the use of a static key. On input fast-path, we already make
    use of static keys in various places, e.g. skb time stamping,
    in RPS, etc. It makes sense to not waste time when we're assured
    that no ingress qdisc is attached anywhere.
    
    Enabling/disabling of that code path is being done via two
    helpers, namely net_{inc,dec}_ingress_queue(), that are being
    invoked under RTNL mutex when a ingress qdisc is being either
    initialized or destructed.
    Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
    Acked-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    4577139b
sch_ingress.c 3.41 KB