+QAT compression PMD needs intermediate buffers to support Deflate compression
+with Dynamic Huffman encoding. RTE_PMD_QAT_COMP_IM_BUFFER_SIZE
+specifies the size of a single buffer, the PMD will allocate a multiple of these,
+plus some extra space for associated meta-data. For GEN2 devices, 20 buffers are
+allocated while for GEN1 devices, 12 buffers are allocated, plus 1472 bytes overhead.
+
+.. Note::
+
+ If the compressed output of a Deflate operation using Dynamic Huffman
+ Encoding is too big to fit in an intermediate buffer, then the
+ operation will be split into smaller operations and their results will
+ be merged afterwards.
+ This is not possible if any checksum calculation was requested - in such
+ case the code falls back to fixed compression.
+ To avoid this less performant case, applications should configure
+ the intermediate buffer size to be larger than the expected input data size
+ (compressed output size is usually unknown, so the only option is to make
+ larger than the input size).
+
+
+Running QAT PMD with minimum threshold for burst size
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If only a small number or packets can be enqueued. Each enqueue causes an expensive MMIO write.
+These MMIO write occurrences can be optimised by setting any of the following parameters:
+
+- qat_sym_enq_threshold
+- qat_asym_enq_threshold
+- qat_comp_enq_threshold
+
+When any of these parameters is set rte_cryptodev_enqueue_burst function will
+return 0 (thereby avoiding an MMIO) if the device is congested and number of packets
+possible to enqueue is smaller.
+To use this feature the user must set the parameter on process start as a device additional parameter::
+
+ -a 03:01.1,qat_sym_enq_threshold=32,qat_comp_enq_threshold=16
+
+All parameters can be used with the same device regardless of order. Parameters are separated
+by comma. When the same parameter is used more than once first occurrence of the parameter
+is used.
+Maximum threshold that can be set is 32.