Re: Re: limited network bandwidth with 3.2.x kernels

[alekcejk@googlemail.com]

В сообщении от Четверг 16 февраля 2012 12:22:29 вы написали:
> Our team has also run into issues with GRO/LRO "stretch ACKs", and
> their negative impact on TCP performance. We have a patch that we've
> been working with that deals with the sender-side issues. It turns out
> that neither the ABC nor non-ABC byte counting quite fixes the stretch
> ACKs issues.
> 
> On the receiver side, the approach of changing tcp_grow_window() and
> __tcp_grow_window() to adjust things in terms of actual packet size
> rather than a fixed 2*MSS sounds great to me as well.
> 
> In terms of the original 3.1 vs 3.2 issue report that started this
> thread, I didn't see any evidence of LRO or GRO causing stretch ACKs.
> (Alexey, would you be able to confim by running "ethtool -k eth0" on
> both kernels?) So it seems that probably the original issue is
> unrelated to stretch ACKs?
> 
> neal

Looks like  "ethtool -k eth0" shows the same with both kernels:

Offload parameters for eth0:
rx-checksumming: on
tx-checksumming: on
scatter-gather: on
tcp-segmentation-offload: off
udp-fragmentation-offload: off
generic-segmentation-offload: on
generic-receive-offload: on
large-receive-offload: off
rx-vlan-offload: off
tx-vlan-offload: off
ntuple-filters: off
receive-hashing: off