[dpdk-dev] [PATCH] net/iavf: fix performance drop

[Lu, Wenzhuo]

> > +use_sse = true;
> > +if ((rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX2) == 1 ||
> > +     rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX512F) == 1) &&
> > +    rte_vect_get_max_simd_bitwidth() >= RTE_VECT_SIMD_256)
> > +use_avx2 = true;
> 
> 
> Not sure if the right path will be selected when avx512 is not true,
> (CC_AVX512_SUPPORT is disable) while check_ret is
> IAVF_VECTOR_OFFLOAD_PATH?
> 
> Currently we have
> 
> if (!use_sse && !use_avx2 && !use_avx512) goto normal;
> 
> Should we also add below check?
> 
> if (!use_avx512 && check_ret == IAVF_VECTOR_OFFLOAD_PATH)
>    goto normal;
Not necessary. As explained in the commit log, AVX2 and SSE support the offload features. The purpose of this patch is to let AVX2 be chosen when offload needed and AVX512 disable.