Re: zerocopy results on GigE

[Jes Sorensen <jes@xxxxxxxxxxxxx>]

>>>>> "David" == David S Miller <davem@xxxxxxxxxx> writes:

David> Pekka Pietikainen writes:
>> Jumbo frames, sender is dual pIII/500 with 32/66 PCI, receiver a
>> dual pII/450 with 32/33, both have 1MB Alteons. CPU use is measured
>> using cyclesoak.  SO_RCVBUF/SO_SNDBUF set to 512k, no other
>> sockopts touched.

David> Strange, cpu usage is close to nothing for sendfile cases yet
David> full bandwidth is not obtained.  Here is what I am getting on
David> UltraSparc systems:

One thing that might be worth investigating is that the AceNIC has
a high latency for reading buffer descriptors. One of the plans I have
is to linearize small skb's before handing them to the NIC.

Jes