netmap bridge can tranmit big packet in line rate ?

[Hooman Fazaeli]

On 5/21/2013 5:10 PM, Barney Cordoba wrote:
>
> --- On Tue, 5/21/13, liujie <liujie at 263.net> wrote:
>
>> From: liujie <liujie at 263.net>
>> Subject: Re: netmap bridge can tranmit big packet in line rate ?
>> To: freebsd-net at freebsd.org
>> Date: Tuesday, May 21, 2013, 5:25 AM
>> Hi, Prof.Luigi RIZZO
>>    
>>  Firstly i should thank you for netmap. I tried to send a
>> e-mail to you
>> yestoday, but it was rejected.
>>
>>  I used two machines to test netmap bridge. all with i7-2600
>> cpu and intel
>> 82599 dual-interfaces card.
>>
>>  One worked as sender and receiver with pkt-gen, the other
>> worked as bridge
>> with bridge.c.
>>
>>  as you said,I feeled comfous too when i saw the big packet
>> performance
>> dropped, i tried to change the memory parameters of
>> netmap(netmap_mem1.c
>> netmap_mem2.c),but it seemed that  can not resove the
>> problem.
>>   60-byte packet send 14882289 pps  recv 
>> 13994753 pps
>>   124-byte     
>>    send   8445770 pps 
>> recv    7628942 pps
>>   252-byte     
>>    send   4529819 pps 
>> recv     3757843 pps
>>   508-byte     
>>    send    2350815 pps 
>> recv    1645647 pps
>>   1514-byte       send 
>>   814288 pps     recv  489133
>> pps
> These numbers indicate you're tx'ing 7.2Gb/s with 60 byte packets and
> 9.8Gb/s with 1514, so maybe you just need a new calculator?
>
> BC
> _______________________________________________
>
AsBarney pointed outalready, your numbers are reasonable. You have almost saturated
the link with 1514 byte packets.In the case of 64 byte packets, you do not achieve line
rate probably because of the congestion on the bus.Can you show us "top -SI" output on the
sender machine?


-- 

Best regards.
Hooman Fazaeli