linux

iv/linux

History

Paolo Abeni 183dea5818 openvswitch: do not propagate headroom updates to internal port

After commit 3a927bc7cf9d ("ovs: propagate per dp max headroom to
all vports") the need_headroom for the internal vport is updated
accordingly to the max needed headroom in its datapath.

That avoids the pskb_expand_head() costs when sending/forwarding
packets towards tunnel devices, at least for some scenarios.

We still require such copy when using the ovs-preferred configuration
for vxlan tunnels:

    br_int
  /       \
tap      vxlan
           (remote_ip:X)

br_phy
     \
    NIC

where the route towards the IP 'X' is via 'br_phy'.

When forwarding traffic from the tap towards the vxlan device, we
will call pskb_expand_head() in vxlan_build_skb() because
br-phy->needed_headroom is equal to tun->needed_headroom.

With this change we avoid updating the internal vport needed_headroom,
so that in the above scenario no head copy is needed, giving 5%
performance improvement in UDP throughput test.

As a trade-off, packets sent from the internal port towards a tunnel
device will now experience the head copy overhead. The rationale is
that the latter use-case is less relevant performance-wise.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

2017-12-02 21:14:59 -05:00

actions.c

openvswitch: Add meter action support

2017-11-13 10:37:07 +09:00

conntrack.c

openvswitch: conntrack: mark expected switch fall-through

2017-10-22 02:01:26 +01:00

conntrack.h

openvswitch: add ct_clear action

2017-10-10 16:38:34 -07:00

datapath.c

net: openvswitch: datapath: fix data type in queue_gso_packets