无意中点进你们的讨论，发现了新大陆。
我的 R5c ，跑 1G 下行，核心 0 、2 基本占用 100%，核心 1 、3 50%左右。
于是按照你们讨论的命令运行了一下，发现只有 vlan offload 是 on 。。。
root@r5c:~# ethtool -k eth1 |grep vlan
rx-vlan-offload: on
tx-vlan-offload: on
rx-vlan-filter: off [fixed]
vlan-challenged: off [fixed]
tx-vlan-stag-hw-insert: off [fixed]
rx-vlan-stag-hw-parse: off [fixed]
rx-vlan-stag-filter: off [fixed]

root@r5c:~# ethtool -k eth1|grep hash
receive-hashing: off [fixed]

root@r5c:~# ethtool -n eth1 rx-flow-hash tcp4
Cannot get RX network flow hashing options: Not supported

root@r5c:~# ethtool -k eth0 |grep ntuple
ntuple-filters: off [fixed]

倒是用 hyper-v 跑的 openwrt 能支持 receive-hashing
root@VM-OpenWrt:~# ethtool -k eth0|grep hash
receive-hashing: on

root@VM-OpenWrt:~# ethtool -n eth1 rx-flow-hash tcp4
TCP over IPV4 flows use these fields for computing Hash flow key:
IP SA
IP DA
L4 bytes 0 & 1 [TCP/UDP src port]
L4 bytes 2 & 3 [TCP/UDP dst port]

root@VM-OpenWrt:~# ethtool -k eth0 |grep ntuple
ntuple-filters: off [fixed]

但不知为何，我两个 openwrt 这个命令都是无 rxq 的结果?
root@r5c:~# ethtool -S eth1
NIC statistics:
tx_packets: 1019723009
rx_packets: 512296019
tx_errors: 0
rx_errors: 0
rx_missed: 5087
align_errors: 0
tx_single_collisions: 0
tx_multi_collisions: 0
unicast: 511816379
broadcast: 479621
multicast: 19
tx_aborted: 0
tx_underrun: 0
tx_octets: 1354315138564
rx_octets: 134934337749
rx_multicast64: 0
tx_unicast64: 1019722967
tx_broadcast64: 7
tx_multicast64: 35
tx_pause_on: 0
tx_pause_off: 0
tx_pause_all: 0
tx_deferred: 0
tx_late_collision: 0
tx_all_collision: 0
tx_aborted32: 0
align_errors32: 0
rx_frame_too_long: 0
rx_runt: 0
rx_pause_on: 0
rx_pause_off: 0
rx_pause_all: 0
rx_unknown_opcode: 0
rx_mac_error: 112
tx_underrun32: 0
rx_mac_missed: 86767
rx_tcam_dropped: 0
tdu: 0
rdu: 200992