linux/net
Alexander Lobakin e131a56348 net: dsa: add GRO support via gro_cells
gro_cells lib is used by different encapsulating netdevices, such as
geneve, macsec, vxlan etc. to speed up decapsulated traffic processing.
CPU tag is a sort of "encapsulation", and we can use the same mechs to
greatly improve overall DSA performance.
skbs are passed to the GRO layer after removing CPU tags, so we don't
need any new packet offload types as it was firstly proposed by me in
the first GRO-over-DSA variant [1].

The size of struct gro_cells is sizeof(void *), so hot struct
dsa_slave_priv becomes only 4/8 bytes bigger, and all critical fields
remain in one 32-byte cacheline.
The other positive side effect is that drivers for network devices
that can be shipped as CPU ports of DSA-driven switches can now use
napi_gro_frags() to pass skbs to kernel. Packets built that way are
completely non-linear and are likely being dropped without GRO.

This was tested on to-be-mainlined-soon Ethernet driver that uses
napi_gro_frags(), and the overall performance was on par with the
variant from [1], sometimes even better due to minimal overhead.
net.core.gro_normal_batch tuning may help to push it to the limit
on particular setups and platforms.

iperf3 IPoE VLAN NAT TCP forwarding (port1.218 -> port0) setup
on 1.2 GHz MIPS board:

5.7-rc2 baseline:

[ID]  Interval         Transfer     Bitrate        Retr
[ 5]  0.00-120.01 sec  9.00 GBytes  644 Mbits/sec  413  sender
[ 5]  0.00-120.00 sec  8.99 GBytes  644 Mbits/sec       receiver

Iface      RX packets  TX packets
eth0       7097731     7097702
port0      426050      6671829
port1      6671681     425862
port1.218  6671677     425851

With this patch:

[ID]  Interval         Transfer     Bitrate        Retr
[ 5]  0.00-120.01 sec  12.2 GBytes  870 Mbits/sec  122  sender
[ 5]  0.00-120.00 sec  12.2 GBytes  870 Mbits/sec       receiver

Iface      RX packets  TX packets
eth0       9474792     9474777
port0      455200      353288
port1      9019592     455035
port1.218  353144      455024

v2:
 - Add some performance examples in the commit message;
 - No functional changes.

[1] https://lore.kernel.org/netdev/20191230143028.27313-1-alobakin@dlink.ru/

Signed-off-by: Alexander Lobakin <bloodyreaper@yandex.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-23 12:32:13 -07:00
..
6lowpan
9p 9pnet: allow making incomplete read requests 2020-03-27 09:29:56 +00:00
802
8021q
appletalk
atm
ax25
batman-adv
bluetooth Bluetooth: Enhanced Connection Complete event belongs to LL Privacy 2020-04-16 12:43:03 +03:00
bpf bpf: Fix build warning regarding missing prototypes 2020-03-28 18:13:18 +01:00
bpfilter SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
bridge net: bridge: vlan options: move the tunnel command to the nested attribute 2020-03-20 08:52:20 -07:00
caif net: caif: use true,false for bool variables 2020-04-22 19:37:48 -07:00
can
ceph libceph: directly skip to the end of redirect reply 2020-03-30 12:42:41 +02:00
core net: Add testing sysfs attribute 2020-04-20 12:43:24 -07:00
dcb
dccp
decnet Remove DST_HOST 2020-03-23 21:57:44 -07:00
dns_resolver KEYS: Don't write out to userspace while holding key semaphore 2020-03-29 12:40:41 +01:00
dsa net: dsa: add GRO support via gro_cells 2020-04-23 12:32:13 -07:00
ethernet
ethtool drivers: Remove inclusion of vermagic header 2020-04-21 13:27:37 -07:00
hsr hsr: check protocol version in hsr_newlink() 2020-04-07 18:34:18 -07:00
ieee802154
ife
ipv4 net: ipv4: remove redundant assignment to variable rc 2020-04-20 16:26:58 -07:00
ipv6 ipv6: Honor all IPv6 PIO Valid Lifetime values 2020-04-23 12:29:21 -07:00
iucv
kcm net: kcm: kcmproc.c: Fix RCU list suspicious usage warning 2020-03-16 17:14:02 -07:00
key
l2tp l2tp: Allow management of tunnels and session in user namespace 2020-04-08 14:30:46 -07:00
l3mdev
lapb
llc
mac80211 mac80211: fix channel switch trigger from unknown mesh peer 2020-04-15 09:54:26 +02:00
mac802154
mpls net: add net available in build_state 2020-03-29 22:30:57 -07:00
mptcp mptcp: fix double-unlock in mptcp_poll 2020-04-12 21:04:08 -07:00
ncsi
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-04-16 14:52:29 -07:00
netlabel
netlink Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-25 18:58:11 -07:00
netrom
nfc
nsh
openvswitch net: openvswitch: use hlist_for_each_entry_rcu instead of hlist_for_each_entry 2020-04-02 17:48:12 -07:00
packet
phonet
psample
qrtr net: qrtr: Add tracepoint support 2020-04-22 12:55:54 -07:00
rds net/rds: Use ERR_PTR for rds_message_alloc_sgs() 2020-04-15 12:33:29 -07:00
rfkill
rose
rxrpc rxrpc: Fix DATA Tx to disable nofrag for UDP on AF_INET6 socket 2020-04-14 16:26:47 -07:00
sched net/sched: act_ct: update nf_conn_acct for act_ct SW offload in flowtable 2020-04-22 12:48:17 -07:00
sctp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-30 20:48:43 -07:00
smc
strparser
sunrpc NFS client updates for Linux 5.7 2020-04-07 13:51:39 -07:00
switchdev
tipc tipc: fix incorrect increasing of link window 2020-04-15 16:23:33 -07:00
tls net/tls: fix const assignment warning 2020-04-08 14:34:02 -07:00
unix
vmw_vsock
wimax
wireless nl80211: fix NL80211_ATTR_FTM_RESPONDER policy 2020-04-14 12:28:48 +02:00
x25
xdp xsk: Add missing check on user supplied headroom size 2020-04-15 13:07:18 +02:00
xfrm Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2020-03-30 10:59:20 -07:00
compat.c
Kconfig net: Fix CONFIG_NET_CLS_ACT=n and CONFIG_NFT_FWD_NETDEV={y, m} build 2020-03-25 12:24:33 -07:00
Makefile
socket.c for-5.7/io_uring-2020-03-29 2020-03-30 12:18:49 -07:00
sysctl_net.c