doc: update description in qat compression guide
Checks
Commit Message
Added limitations description for the QAT compression PMD.
Updated intermediate buffers description in qat.rst file.
Signed-off-by: Tomasz Jozwiak <tomaszx.jozwiak@intel.com>
---
doc/guides/compressdevs/qat_comp.rst | 4 ++++
doc/guides/cryptodevs/qat.rst | 6 ++++--
2 files changed, 8 insertions(+), 2 deletions(-)
Comments
> -----Original Message-----
> From: Jozwiak, TomaszX
> Sent: Monday, January 14, 2019 3:11 PM
> To: dev@dpdk.org; Trahe, Fiona <fiona.trahe@intel.com>; Jozwiak, TomaszX
> <tomaszx.jozwiak@intel.com>; De Lara Guarch, Pablo <pablo.de.lara.guarch@intel.com>
> Subject: [PATCH] doc: update description in qat compression guide
>
> Added limitations description for the QAT compression PMD.
> Updated intermediate buffers description in qat.rst file.
>
> Signed-off-by: Tomasz Jozwiak <tomaszx.jozwiak@intel.com>
Acked-by: Fiona Trahe <fiona.trahe@intel.com>
> > Added limitations description for the QAT compression PMD.
> > Updated intermediate buffers description in qat.rst file.
> >
> > Signed-off-by: Tomasz Jozwiak <tomaszx.jozwiak@intel.com>
> Acked-by: Fiona Trahe <fiona.trahe@intel.com>
Applied, thanks
@@ -35,6 +35,10 @@ Limitations
* Compressdev level 0, no compression, is not supported.
* Queue pairs are not thread-safe (that is, within a single queue pair, RX and TX from different lcores is not supported).
* No BSD support as BSD QAT kernel driver not available.
+* Number of segments in mbuf chains in the op must be <= RTE_PMD_QAT_COMP_SGL_MAX_SEGMENTS from the config file.
+* When using Deflate dynamic huffman encoding for compression, the input size (op.src.length)
+ must be < CONFIG_RTE_PMD_QAT_COMP_IM_BUFFER_SIZE from the config file,
+ see :ref:`building_qat_config` for more details.
Installation
@@ -145,6 +145,8 @@ Quick instructions for QAT compressdev PMD are as follows:
make
+.. _building_qat_config:
+
Build Configuration
~~~~~~~~~~~~~~~~~~~
@@ -180,8 +182,8 @@ An extra (max_inflight_ops x 16) bytes per queue_pair will be used for every inc
QAT compression PMD needs intermediate buffers to support Deflate compression
with Dynamic Huffman encoding. CONFIG_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 plus
-1472 bytes are allocated.
+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::