cardigliano at ntop
May 30, 2012, 6:49 AM
Post #4 of 4
(370 views)
Permalink
|
Chris
we are still running some experiments, as the change was not satisfactory with all packet types so we reverted it.
Stay tuned.
Alfredo
On May 30, 2012, at 2:49 PM, Chris Wakelin wrote:
> I noticed you modified the rss ixgbe DNA driver yesterday, so I gave it
> a try :-)
>
> It seemed to do the right thing with the flows, though my CPU usage was
> near 99% on some threads.
>
> You then reversed the changes. Did you find it caused problems, or is it
> just too experimental?
>
> Best Wishes,
> Chris
>
> On 28/05/12 23:35, Alfredo Cardigliano wrote:
>> Chris
>> thank you for the pointers!
>> Some preliminary tests reprogramming rss key and redirection table are promising.
>>
>> Regards
>> Alfredo
>>
>> On May 28, 2012, at 7:23 PM, Chris Wakelin wrote:
>>
>>> I've been looking at the issue of multiqueue RSS hashing in ixgbe (and
>>> presumably igb), which is one of the things libzero is supposed to help
>>> with.
>>>
>>> The problem is that (at least in some cases) traffic from X->Y may end
>>> up in a different queue, and therefore different CPU core, to that from
>>> Y->X.
>>>
>>> I found some patches that are supposed to help
>>>
>>> http://www.mail-archive.com/e1000-devel [at] lists/msg04364.html
>>>
>>> and
>>>
>>> http://kerneltrap.org/mailarchive/linux-netdev/2010/12/18/6292110
>>>
>>> So it appears that the hashing algorithm can be modified in the driver!
>>>
>>> In the ensuing discussion on kerneltrap.org
>>>
>>> http://kerneltrap.org/mailarchive/linux-netdev/2011/1/3/6292774
>>>
>>> the author says that when flow-director is enabled, the patch isn't needed.
>>>
>>> So if I turn on "ntuple" with "ethtool -K eth1 ntuple: on", with no
>>> filtering rules, would that mean the queues now match?
>>>
>>> My testing has been pretty inconclusive. Certainly, even in the default
>>> modes, I get *some* traffic where X->Y and Y->X are in the same queue,
>>> but of course you'd probably expect that to happen in 1/N cases for N
>>> queues.
>>>
>>> Best Wishes,
>>> Chris
>>>
>>> --
>>> --+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+-
>>> Christopher Wakelin, c.d.wakelin [at] reading
>>> IT Services Centre, The University of Reading, Tel: +44 (0)118 378 2908
>>> Whiteknights, Reading, RG6 6AF, UK Fax: +44 (0)118 975 3094
>>> _______________________________________________
>>> Ntop-misc mailing list
>>> Ntop-misc [at] listgateway
>>> http://listgateway.unipi.it/mailman/listinfo/ntop-misc
>>
>> _______________________________________________
>> Ntop-misc mailing list
>> Ntop-misc [at] listgateway
>> http://listgateway.unipi.it/mailman/listinfo/ntop-misc
>
>
> --
> --+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+-
> Christopher Wakelin, c.d.wakelin [at] reading
> IT Services Centre, The University of Reading, Tel: +44 (0)118 378 2908
> Whiteknights, Reading, RG6 6AF, UK Fax: +44 (0)118 975 3094
> _______________________________________________
> Ntop-misc mailing list
> Ntop-misc [at] listgateway
> http://listgateway.unipi.it/mailman/listinfo/ntop-misc
_______________________________________________
Ntop-misc mailing list
Ntop-misc [at] listgateway
http://listgateway.unipi.it/mailman/listinfo/ntop-misc
|
