Chelsio Communications Terminator Series Installation And User Manual page 67

Chapter II. Network (NIC/TOE)
generic-receive-offload
Now the
there are two offload options here:
This is because on this Linux system (RHEL6.0), the kernel supports both GRO and LRO. As
mentioned earlier, GRO is always the preferred option when both of them are present. On other
systems LRO might be the only available option. Then
and off as well.
When Linux's GRO is enabled, Chelsio's driver provides two GRO-related statistics. They are
displayed using the following command:
[root@host~]# ethtool -S eth6
...
GROPackets : 0
GROMerged : 897723
...
GROPackets
is the number of held packets. Those are candidate packets held by the kernel to be
processed individually or to be merged to larger packets. This number is usually zero.
GROMerged is the number of packets that merged to larger packets. Usually this number increases
if there is any continuous traffic stream present.
ethtool can also be used to switch off the GRO/LRO options when necessary:
[root@host~]# ethtool -K eth6 gro off
[root@host~]# ethtool -k eth6
Offload parameters for eth6:
rx-checksumming: on
tx-checksumming: on
scatter-gather: on
tcp-segmentation-offload: on
udp-fragmentation-offload: off
generic-segmentation-offload: on
generic-receive-offload: off
large-receive-offload: off
The output above shows a disabled GRO.
Chelsio Unified Wire for Linux
option is on. This means GRO is enabled. Please note that
generic-receive-offload
ethtool
large-receive-offload
and
could be used to switch LRO on
.
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