+- ``mr_mempool_reg_en`` parameter [int]
+
+ A nonzero value enables implicit registration of DMA memory of all mempools
+ except those having ``RTE_MEMPOOL_F_NON_IO``. This flag is set automatically
+ for mempools populated with non-contiguous objects or those without IOVA.
+ The effect is that when a packet from a mempool is transmitted,
+ its memory is already registered for DMA in the PMD and no registration
+ will happen on the data path. The tradeoff is extra work on the creation
+ of each mempool and increased HW resource use if some mempools
+ are not used with MLX5 devices.
+
+ Enabled by default.
+