Re: [PATCH] app/testpmd: improve sse based macswap

[Ferruh Yigit <ferruh.yigit@amd.com>]

On 7/16/2024 7:37 AM, Vipin Varghese wrote:
> Goal of the patch is to improve SSE macswap on x86_64 by reducing
> the stalls in backend engine. Original implementation of the SSE
> macswap makes loop call to multiple load, shuffle & store. Using
> SIMD ISA interleaving we can reduce the stalls for
>  - load SSE token exhaustion
>  - Shuffle and Load dependency
> 
> Also other changes which improves packet per second are
>  - Filling access to MBUF for offload flags which is separate cacheline,
>  - using register keyword
> 
> Build test using meson script:
> ``````````````````````````````
> 
> build-gcc-static
> buildtools
> build-gcc-shared
> build-mini
> build-clang-static
> build-clang-shared
> build-x86-generic
> 
> Test Results:
> `````````````
> 
> Platform-1: AMD EPYC SIENA 8594P @2.3GHz, no boost
> 
> ------------------------------------------------
> TEST IO 64B: baseline <NIC : MPPs>
>  - mellanox CX-7 2*200Gbps : 42.0
>  - intel E810 1*100Gbps : 82.0
>  - intel E810 2*200Gbps (2CQ-DA2): 82.45
> ------------------------------------------------
> TEST MACSWAP 64B: <NIC : Before : After>
>  - mellanox CX-7 2*200Gbps : 31.533 : 31.90
>  - intel E810 1*100Gbps : 50.380 : 47.0
>  - intel E810 2*200Gbps (2CQ-DA2): 48.840 : 49.827
> ------------------------------------------------
> TEST MACSWAP 128B: <NIC : Before: After>
>  - mellanox CX-7 2*200Gbps: 30.946 : 31.770
>  - intel E810 1*100Gbps: 49.386 : 46.366
>  - intel E810 2*200Gbps (2CQ-DA2): 47.979 : 49.503
> ------------------------------------------------
> TEST MACSWAP 256B: <NIC: Before: After>
>  - mellanox CX-7 2*200Gbps: 32.480 : 33.150
>  - intel E810 1 * 100Gbps: 45.29 : 44.571
>  - intel E810 2 * 200Gbps (2CQ-DA2): 45.033 : 45.117
> ------------------------------------------------
> 
> Platform-2: AMD EPYC 9554 @3.1GHz, no boost
> 
> ------------------------------------------------
> TEST IO 64B: baseline <NIC : MPPs>
>  - intel E810 2*200Gbps (2CQ-DA2): 82.49
> ------------------------------------------------
> <NIC intel E810 2*200Gbps (2CQ-DA2): Before : After>
> TEST MACSWAP: 1Q 1C1T
>  64B: : 45.0 : 45.54
> 128B: : 44.48 : 44.43
> 256B: : 42.0 : 41.99
> +++++++++++++++++++++++++
> TEST MACSWAP: 2Q 2C2T
>  64B: : 59.5 : 60.55
> 128B: : 56.78 : 58.1
> 256B: : 41.85 : 41.99
> ------------------------------------------------
> 
> Signed-off-by: Vipin Varghese <vipin.varghese@amd.com>
>

Hi Bruce, John,

Can you please help testing macswap performance with this patch on Intel
platforms, to be sure it is not causing regression?

Other option is to get this patch for -rc3 and tested there, with the
condition to remove it in any regression, if this help testing the patch?

Thanks,
ferruh