On 4/27/2021 3:57 AM, Zhang, Qi Z wrote:

quoted

-----Original Message-----
From: Lu, Wenzhuo <redacted>
Sent: 2021年4月27日 9:51
To: Zhang, Qi Z <redacted>; dev@dpdk.org
Subject: RE: [dpdk-dev] [PATCH] net/iavf: fix performance drop

quoted

quoted

+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.

OK, now I understand it, I will suggest to change the commit log.

From 
AVX2 and SSE don't have the offload path.

To 
AVX2 and SSE Tx path already support offloads but can't selected.

Isn't this related to the _Rx_ path?

If you agree, will apply above during change during patch merge.