[dpdk-dev] [PATCH v2] app/testpmd: tx pkt clones parameter in flowgen

[Ferruh Yigit]

On 1/21/2021 6:05 PM, Igor Russkikh wrote:
> When testing high performance numbers, it is often that CPU performance
> limits the max values device can reach (both in pps and in gbps)
> 
> Here instead of recreating each packet separately, we use clones counter
> to resend the same mbuf to the line multiple times.
> 
> PMDs handle that transparently due to reference counting inside of mbuf.
> 
> Reaching max PPS on small packet sizes helps here:
> Some data from our 2 port x 50G device. Using 2*6 tx queues, 64b packets,
> PowerEdge R7525, AMD EPYC 7452:
> 
> ./build/app/dpdk-testpmd -l 32-63  -- --forward-mode=flowgen \
>    --rxq=6 --txq=6  --disable-crc-strip --burst=512 \
>    --flowgen-clones=0 --txd=4096 --stats-period=1 --txpkts=64
> 
> Gives ~46MPPS TX output:
> 
>    Tx-pps:     22926849          Tx-bps:  11738590176
>    Tx-pps:     23642629          Tx-bps:  12105024112
> 
> Setting flowgen-clones to 512 pushes TX almost to our device
> physical limit (68MPPS) using same 2*6 queues(cores):
> 
>    Tx-pps:     34357556          Tx-bps:  17591073696
>    Tx-pps:     34353211          Tx-bps:  17588802640
> 
> Doing similar measurements per core, I see one core can do
> 6.9MPPS (without clones) vs 11MPPS (with clones)
> 
> Verified on Marvell qede and atlantic PMDs.
> 
> v2:
>    - fixed warning on uninit var
> v1:
>    - fixes on Ferruh's comments
> 
> rfc v2: http://patchwork.dpdk.org/patch/78800/
>    - increment ref counter for each mbuf pointer copy
> rfc v1: http://patchwork.dpdk.org/patch/78674/
> 
> Signed-off-by: Igor Russkikh <irusskikh at marvell.com>

Reviewed-by: Ferruh Yigit <ferruh.yigit at intel.com>

Also a testpmd command to set the 'flowgen-clones' can be useful, for 
interactive mode. If you have time for it, can you please work on it too?


Applied to dpdk-next-net/main, thanks.