> -----Original Message-----
> From: dev <dev-boun...@dpdk.org> On Behalf Of Wenzhuo Lu
> Sent: Monday, April 26, 2021 1:30 PM
> To: dev@dpdk.org
> Cc: Lu, Wenzhuo <wenzhuo...@intel.com>
> Subject: [dpdk-dev] [PATCH] net/iavf: fix performance drop
>
> AVX2 and SSE don't have the offload path.
> Not necessary doing any check. Or the scalar path will be chosen.
>
> Fixes: eff56a7b9f97 ("net/iavf: add offload path for Rx AVX512")
>
> Signed-off-by: Wenzhuo Lu <wenzhuo...@intel.com>
> ---
> drivers/net/iavf/iavf_rxtx.c | 12 +++++-------
> 1 file changed, 5 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/iavf/iavf_rxtx.c b/drivers/net/iavf/iavf_rxtx.c index
> 3f3cf63..0ba19dbf 100644
> --- a/drivers/net/iavf/iavf_rxtx.c
> +++ b/drivers/net/iavf/iavf_rxtx.c
> @@ -2401,13 +2401,11 @@
> check_ret = iavf_rx_vec_dev_check(dev);
> if (check_ret >= 0 &&
> rte_vect_get_max_simd_bitwidth() >= RTE_VECT_SIMD_128) {
> - if (check_ret == IAVF_VECTOR_PATH) {
> - 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;
> - }
> + 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;
>
> #ifdef CC_AVX512_SUPPORT
> if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX512F) == 1 &&
> --
> 1.9.3
