From: Matan Azrad <ma...@nvidia.com>
Sent: Wednesday, January 6, 2021 3:57 PM
To: Trahe, Fiona <fiona.tr...@intel.com>; ashish.gu...@marvell.com
Cc: dev@dpdk.org; NBU-Contact-Thomas Monjalon <tho...@monjalon.net>
Subject: DPDK compress API - questions
Hi Fiona, Ashish
I'm going to add new HW offload compress PMD for mlx5 devices in 21.02.
I have some questions on the API:
#define RTE_COMP_FF_NONCOMPRESSED_BLOCKS (1ULL << 11)
/**< Creation of non-compressed blocks using RTE_COMP_LEVEL_NONE is supported */
1. What does it mean non-compressed block ? DMA?
[Fiona] Not exactly. E.g. for Deflate, if the output is non-compressed blocks,
it still has the deflate headers.
So is not a direct DMA of the input data. As this may not be supported by all
PMDs it is exposed in a feature flag.
2. Does Using RTE_COMP_LEVEL_NONE or RTE_COMP_ALGO_NULL the same?
[Fiona] No. ALGO_NULL would be DMA.
/**< No compression.
* Pass-through, data is copied unchanged from source buffer to
* destination buffer.
*/
LEVEL_NONE should output the data in the correct format for the specified
algorithm.
Probably I will add more question later.
Thanks
Matan
