...
tcp-segmentation-offload: on
tx-tcp-segmentation: on
tx-tcp-ecn-segmentation: off [fixed]
tx-tcp-mangleid-segmentation: off
tx-tcp6-segmentation: on
udp-fragmentation-offload: off [fixed]
generic-segmentation-offload: on
...
I have some other Debian Jessie systems also using the igb-driver and tso is always enabled here by default (but not the same NIC). (Kernel 3.16)
I also have a Proxmox VE system on kernel 4.4 with exactly the same quad NIC that i suspect do not use the kernel source igb-drivers as it has a lot more params that also has tso enabled correctly.
# Proxmox VE system (full TSO by default)
#ethtool -i eth1
driver: igb
version: 5.3.5.3
firmware-version: 3.19, 0x00013cbf
bus-info: 0000:03:00.1
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: no
# Debian Stretch systems (half-enabled TSO by default)
# ethtool -i eth2
driver: igb
version: 5.4.0-k
firmware-version: 0.0.0
expansion-rom-version:
bus-info: 0000:00:14.2
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: no
The NIC that the "working" and the "non-working" system have is HP NC365T, which is based on intel 82580.
The other "non-working" Debian Stretch system is a Intel Rangeley Atom c2758 supermicros system with a quad intel I354 network controller embedded.
I tried booting the stretch system with kernel 3.16 from Debian Jessie to get the same drivers like my working systems but no change. Then I noticed that systemd got the ability to change exactly these offloads in the last systemd version 232 which arrived in testing in the end of 2016 so I am thinking that this might have something to do with this, but I have not found anything (mostly because I don't even really know where to look)
I also tried to not having one of the interfaces in any kind of bond or vlan subinterface in case those were changing some stuff but no changes in behaviour.
So to my questions:
- Can anyone think of a reason why tx-tcp-segmentation offload is disabled by default (and not tcp segmentation offload in general)
- Do you have any tips to troubleshoot this?
- As this default combination of out-of-the-box settings is bad for fq with pacing performance, and it seems to somewhat be the default now for two different igb-systems I thought I should give you a heads up.
Regards,
Hans-Kristian