From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by dpdk.org (Postfix) with ESMTP id 7939E2BE1 for ; Wed, 23 May 2018 17:54:17 +0200 (CEST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 23 May 2018 08:54:16 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,433,1520924400"; d="scan'208";a="226648004" Received: from silpixa00399501.ir.intel.com ([10.237.223.69]) by orsmga005.jf.intel.com with ESMTP; 23 May 2018 08:54:14 -0700 From: Lee Daly To: pablo.de.lara.guarch@intel.com Cc: dev@dpdk.org, hailiangx.e.wang@intel.com, Lee Daly Date: Wed, 23 May 2018 16:54:01 +0100 Message-Id: <1527090841-75874-1-git-send-email-lee.daly@intel.com> X-Mailer: git-send-email 2.7.4 Subject: [dpdk-dev] [PATCH] doc/compress: add compression level guide for ISA-L X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 May 2018 15:54:18 -0000 This expands the ISA-L documentation to give more a detailed explanation of the mapping between the compressdev API levels and PMD levels. Signed-off-by: Lee Daly --- doc/guides/compressdevs/isal.rst | 63 +++++++++++++++++++++++++++++++++++----- 1 file changed, 55 insertions(+), 8 deletions(-) diff --git a/doc/guides/compressdevs/isal.rst b/doc/guides/compressdevs/isal.rst index 2024437..9c8dfea 100644 --- a/doc/guides/compressdevs/isal.rst +++ b/doc/guides/compressdevs/isal.rst @@ -6,7 +6,8 @@ ISA-L Compression Poll Mode Driver The ISA-L PMD (**librte_pmd_isal_comp**) provides poll mode compression & decompression driver support for utilizing Intel ISA-L library, -which implements the deflate algorithm for both compression and decompression +which implements the deflate algorithm for both Deflate(compression) and Inflate(decompression). + Features -------- @@ -15,25 +16,71 @@ ISA-L PMD has support for: Compression/Decompression algorithm: -* DEFLATE + * DEFLATE Huffman code type: -* FIXED -* DYNAMIC + * FIXED + * DYNAMIC Window size support: -* 32K + * 32K + +Level guide: + +The ISA-L levels have been mapped to somewhat correspond to the same ZLIB level, i.e. ZLIB L1 gives a compression ratio similar to ISA-L L1. +Compressdev level 0 enables "No Compression", which passes the uncompressed data to the output buffer, plus deflate headers. +The ISA-L library does not support this, therefore compressdev level 0 is not supported. + +The compressdev API has 10 levels, 0-9. ISA-L has 4 levels of compression, 0-3. +As a result the level mappings from the API to the PMD are shown below. + +.. _table_ISA-L_compression_levels: + +.. table:: Level mapping from Compressdev to ISA-L PMD. + + +-------------+----------------------------------------------+-----------------------------------------------+ + | Compressdev | PMD Functionality | Internal ISA-L | + | API Level | | Level | + +=============+==============================================+===============================================+ + | 0 | No compression, Not Supported | --- | + +-------------+----------------------------------------------+-----------------------------------------------+ + | 1 | Dynamic (Fast compression) | 1 | + +-------------+----------------------------------------------+-----------------------------------------------+ + | 2 | Dynamic | 2 | + | | (Higher compression ratio) | | + +-------------+----------------------------------------------+-----------------------------------------------+ + | 3 | Dynamic | 3 | + | | (Best compression ratio) | (Level 2 if | + | | | no AVX512/AVX2) | + +-------------+----------------------------------------------+-----------------------------------------------+ + | 4 | Dynamic (Best compression ratio) | Same as above | + +-------------+----------------------------------------------+-----------------------------------------------+ + | 5 | Dynamic (Best compression ratio) | Same as above | + +-------------+----------------------------------------------+-----------------------------------------------+ + | 6 | Dynamic (Best compression ratio) | Same as above | + +-------------+----------------------------------------------+-----------------------------------------------+ + | 7 | Dynamic (Best compression ratio) | Same as above | + +-------------+----------------------------------------------+-----------------------------------------------+ + | 8 | Dynamic (Best compression ratio) | Same as above | + +-------------+----------------------------------------------+-----------------------------------------------+ + | 9 | Dynamic (Best compression ratio) | Same as above | + +-------------+----------------------------------------------+-----------------------------------------------+ + +.. Note:: + + The above table only shows mapping when API calls for dynamic compression. + For fixed compression, regardless of API level, internally ISA-L level 0 is always used. Limitations ----------- -* Chained mbufs are not supported, for future release. +* Chained mbufs will not be supported until a future release, meaning max data size being passed to PMD through a single mbuf is 64K - 1. If data is larger than this it will need to be split up and sent as multiple operations. -* Compressdev level 0, no compression, is not supported. ISA-L level 0 used for fixed huffman codes. +* Compressdev level 0, no compression, is not supported. -* Checksums are not supported, for future release. +* Checksums will not be supported until future release. Installation ------------ -- 2.7.4