[Click] 10GE Click performance

[Eddie Kohler]

Hi Luigi,

So just to check: Does #3 include our allocator fixes?

It might be possible to get rid of at least one of the copies in #3.

Eddie


On 1/20/12 5:12 PM, Luigi Rizzo wrote:
> On Fri, Jan 20, 2012 at 10:21:15PM +0200, Beyers Cronje wrote:
>> Hi Luigi,
>>
>> Have you guys released the driver for linux yet, or is it still a work in
>> progress? How does the libpcap emulation compare performance wise with a
>> native netmap driver?
>
> the linux driver is not ready yet, though today we managed to
> send the first packets with linux-netmap. I am hoping we can get
> something ready for distribution  in 2-3 weeks.
>
> As for native vs libpcap, here are the most recent numbers i have are
> for something equivalent to FromDevice ->  Queue ->  ToDevice :
>
>    1.	pure netmap (zero copy)		14.2 Mpps @ 1.6  GHz
>    2.	pcap_dispatch(pcap_inject())	 8.5 Mpps @ 2.93 GHz
>    3.	click userspace+netmap/libpcap	 3.95Mpps @ 2.93 GHz
>    4.	click userspace+bpf/libpcap 	 0.49Mpps @ 2.93 GHz
>
> In terms of data copies and memory allocations:
> #1 is really zero-copy, #2 does one copy, #3 does two copies and
> one allocation (and the allocator was the bottleneck, fixed last
> summer with Eddie), #4 is copies plus one Packet allocation plus
> one syscall plus two mbuf allocations.
>
> cheers
> luigi
>
> 	
>
>> Beyers
>>
>> On Fri, Jan 20, 2012 at 8:54 PM, Luigi Rizzo<rizzo at iet.unipi.it>  wrote:
>>
>>> On Fri, Jan 20, 2012 at 09:19:43AM -0800, Roman Chertov wrote:
>>>>>
>>>>> Kinda wonder how prepared click is for the netmap work being done and
>>>>> 10Gb performance, and if it will help
>>> i
>
>>>> I recall reading on the list that netmap maintains a TX ring and as such
>>>> it is not friendly to Click configs that can hold on to some packets for
>>>> a while.
>>>>
>>>> FromDevice(ethX) ->  cl::Classifier(...)[0]
>>>>                    ->  Queue
>>>>                    ->  DelayShaper(DELAY)
>>>>                    ->  outQ;
>>>>
>>>> cl[1] ->  outQ;
>>>>
>>>> Any clarifications from people familiar with netmap?
>>>
>>> Click uses the libpcap emulation to run on top of netmap,
>>> so it doesn't know anything about the netmap rings.
>>> Incoming frames are copied into Click's Packets in the callback
>>> passed tp pcap_dispatch(), and they
>>> can be stored for as long as you like provided there is
>>> enough (userspace) memory.
>>> When it is time to transmit, pcap_inject() copies the payload
>>> from the Packet to the netmap ring and the packet goes out.
>>>
>>> The two copies are moderately expensive but we are still talking
>>> 3-4Mpps for FromDevice ->  EtherSwitch ->  ToDevice .
>>>
>>> Anything that takes a timestamp is going to hurt much more
>>> than the memory copies.
>>>
>>> cheers
>>> luigi
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>>> click at amsterdam.lcs.mit.edu
>>> https://amsterdam.lcs.mit.edu/mailman/listinfo/click
>>>
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