Below is my conclusion for this bug. An expert of x86 is required to follow-up.
Summary: - CPU: Intel Skylake - Linux environment: Ubuntu 18.04 - Compiler: GCC 7 or 8 - Scenario: testpmd crashes when it starts forwarding - Behaviour: AVX2 version of rte_memcpy() fails if optimized for AVX512 - Context: inline rte_memcpy() is called from inline rte_mempool_put_bulk(), called from mlx5_tx_complete() (inline or not) - Analysis: AVX512 optimization changes vmovdqu to vmovdqu8 Latest status can be found in Bugzilla: https://bugs.dpdk.org/show_bug.cgi?id=97#c35