[dpdk-dev] [PATCH] fm10k: conditionally disable RSS during device initialization

[Chen, Jing D]

Hi, Frasca,



> -----Original Message-----
> From: Michael Frasca [mailto:michael.frasca at oracle.com]
> Sent: Wednesday, March 23, 2016 9:43 PM
> To: Chen, Jing D
> Cc: dev at dpdk.org
> Subject: Re: [PATCH] fm10k: conditionally disable RSS during device
> initialization
> 
> Hi Jing,
> 
> I ran into this issue while trying to run experiments with different RSS
> configurations (no RSS being one cases). It is not clear to me that setting this
> register to zero is the best way to disable RSS.
> 
> After digging further, I have a theory that I'm having this issues because I've
> only attached my DPDK application to SR-IOV ports. In
> fm10k_dev_dglort_map_configure(), I see that 'RSS Length' is set for the
> DGLORT
> decoder. However, it appears that this is only invoked for physical functions.
> 
> Could this be my problem? Is it required that I bind to the physical function
> if I want to properly manipulate RSS?
> 
> Thanks,
> Mike
> 
I don't know exactly what problem you ran into. I think we needn't worry about 
those DGLORT setting when using VF device.

I've followed steps to use SRIOV device with RSS enabled and disabled, both
are worked well from my side after applying your patch. Below is my setup.

1. PF with Linux driver "fm10k-next_0.19.3".
2. DPDK with latest code from master branch, apply your patch.
3. Use 1 VF device created by kernel driver.
4. use l3fwd with " ./examples/l3fwd/build/l3fwd -c fc -n 4 -- -p 0x1 --config="(0,0,2),(0,1,2),(0,2,3),(0,3,3)""
    with RSS enabled. After sending packets, I can see all 4 queues received packets.
5. use l3fwd with " ./examples/l3fwd/build/l3fwd -c fc -n 4 -- -p 0x1 --config="(0,0,2)""
    with RSS disabled. After sending packets, I can see queue 0 received packets.

Can you explain what actual problem is?
We can talk offline.