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To: Stefan Binna <stefan.binna@salzburgresearch.at>,
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From: Declan Doherty <declan.doherty@intel.com>
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Date: Tue, 1 Sep 2015 17:03:31 +0100
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Cc: Thomas Pfeiffenberger <thomas.pfeiffenberger@salzburgresearch.at>,
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Subject: Re: [dpdk-dev] Fast Failover Test Results
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On 01/09/15 14:31, Stefan Binna wrote:
> Hi @all,
>
> I've conducted some fast failover tests on a SDN infrastructure, whereby
> following three configurations were used for the device under test (DUT):
>
> - Intel 82574L with default driver e1000e
> - Intel 82574L with DPDK
> - Realtek RTL8111/8168/8411 PCI Express with default driver r8169
>
> There were two paths connected to the DUT, e.g. Path 1 and Path 2.
> So by default Path 1 had been used. When Path 1 was disconnected, the
> time it took to switch to Path 2 had been measured by counting the lost
> packets.
> Several tests have been conducted and the median calculated.
>
> Terminology:
>
> Median FF: Median fast failover time / ms
> Median LP: Median lost packets / packet(s)
>
>                       Median FF   Median LP
>
> DPDK            1700            3363
> Intel              350              690
> Realtek         350              695
>
> Anyone an idea why DPDK is so "slow"?
>
> Best regards,
>     Stefan.

Hey Stefan,

A couple of questions regarding your setup which will hopefully help me 
figure out what the issue is.

- Are you just running in active backup mode or are you using  one of 
the other bonding modes.
- What is down stream of the DUT, is it a switch or are you just 
directly connected to another system?

I'm not sure if the 82574L has LSC interrupt support in DPDK, I'll check 
that out, but if it doesn't the PMD need will be polling the link status 
which could be slowing down detection of the link going down and the 
fail over to the over port.

Declan