[ovs-dev] [PATCH 1/8] datapath: do not propagate headroom updates to internal port
Greg Rose
gvrose8192 at gmail.com
Wed Feb 14 23:18:03 UTC 2018
From: paolo abeni <pabeni at redhat.com>
Upstream commit:
commit 183dea5818315c0a172d21ecbcd2554894bf01e3
Author: Paolo Abeni <pabeni at redhat.com>
Date: Thu Nov 30 15:35:33 2017 +0100
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 at redhat.com>
Acked-by: Pravin B Shelar <pshelar at ovn.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
Cc: paolo abeni <pabeni at redhat.com>
Signed-off-by: Greg Rose <gvrose8192 at gmail.com>
---
datapath/vport-internal_dev.c | 19 +------------------
1 file changed, 1 insertion(+), 18 deletions(-)
diff --git a/datapath/vport-internal_dev.c b/datapath/vport-internal_dev.c
index 0aa331a..9bb8751 100644
--- a/datapath/vport-internal_dev.c
+++ b/datapath/vport-internal_dev.c
@@ -149,13 +149,6 @@ internal_get_stats(struct net_device *dev, struct rtnl_link_stats64 *stats)
}
}
-#ifdef HAVE_IFF_PHONY_HEADROOM
-static void internal_set_rx_headroom(struct net_device *dev, int new_hr)
-{
- dev->needed_headroom = new_hr < 0 ? 0 : new_hr;
-}
-#endif
-
static const struct net_device_ops internal_dev_netdev_ops = {
.ndo_open = internal_dev_open,
.ndo_stop = internal_dev_stop,
@@ -165,13 +158,6 @@ static const struct net_device_ops internal_dev_netdev_ops = {
.ndo_change_mtu = internal_dev_change_mtu,
#endif
.ndo_get_stats64 = (void *)internal_get_stats,
-#ifdef HAVE_IFF_PHONY_HEADROOM
-#ifndef HAVE_NET_DEVICE_OPS_WITH_EXTENDED
- .ndo_set_rx_headroom = internal_set_rx_headroom,
-#else
- .extended.ndo_set_rx_headroom = internal_set_rx_headroom,
-#endif
-#endif
};
static struct rtnl_link_ops internal_dev_link_ops __read_mostly = {
@@ -189,7 +175,7 @@ static void do_setup(struct net_device *netdev)
netdev->priv_flags &= ~IFF_TX_SKB_SHARING;
netdev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_OPENVSWITCH |
- IFF_PHONY_HEADROOM | IFF_NO_QUEUE;
+ IFF_NO_QUEUE;
#ifndef HAVE_NEEDS_FREE_NETDEV
netdev->destructor = internal_dev_destructor;
#else
@@ -239,9 +225,6 @@ static struct vport *internal_dev_create(const struct vport_parms *parms)
goto error_free_netdev;
}
-#ifdef HAVE_IFF_PHONY_HEADROOM
- vport->dev->needed_headroom = vport->dp->max_headroom;
-#endif
dev_net_set(vport->dev, ovs_dp_get_net(vport->dp));
internal_dev = internal_dev_priv(vport->dev);
internal_dev->vport = vport;
--
1.8.3.1
More information about the dev
mailing list