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{ "id": 758, "url": "http://patches.dpdk.org/api/covers/758/?format=api", "web_url": "http://patches.dpdk.org/project/dpdk/cover/20240311144706.204831-1-paul.szczepanek@arm.com/", "project": { "id": 1, "url": "http://patches.dpdk.org/api/projects/1/?format=api", "name": "DPDK", "link_name": "dpdk", "list_id": "dev.dpdk.org", "list_email": "dev@dpdk.org", "web_url": "http://core.dpdk.org", "scm_url": "git://dpdk.org/dpdk", "webscm_url": "http://git.dpdk.org/dpdk", "list_archive_url": "https://inbox.dpdk.org/dev", "list_archive_url_format": "https://inbox.dpdk.org/dev/{}", "commit_url_format": "" }, "msgid": "<20240311144706.204831-1-paul.szczepanek@arm.com>", "list_archive_url": "https://inbox.dpdk.org/dev/20240311144706.204831-1-paul.szczepanek@arm.com", "date": "2024-03-11T14:47:01", "name": "[v9,0/5] add pointer compression API", "submitter": { "id": 3199, "url": "http://patches.dpdk.org/api/people/3199/?format=api", "name": "Paul Szczepanek", "email": "paul.szczepanek@arm.com" }, "mbox": "http://patches.dpdk.org/project/dpdk/cover/20240311144706.204831-1-paul.szczepanek@arm.com/mbox/", "series": [ { "id": 31461, "url": "http://patches.dpdk.org/api/series/31461/?format=api", "web_url": "http://patches.dpdk.org/project/dpdk/list/?series=31461", "date": "2024-03-11T14:47:01", "name": "add pointer compression API", "version": 9, "mbox": "http://patches.dpdk.org/series/31461/mbox/" } ], "comments": "http://patches.dpdk.org/api/covers/758/comments/", "headers": { "Return-Path": "<dev-bounces@dpdk.org>", "X-Original-To": "patchwork@inbox.dpdk.org", "Delivered-To": "patchwork@inbox.dpdk.org", "Received": [ "from mails.dpdk.org (mails.dpdk.org [217.70.189.124])\n\tby inbox.dpdk.org (Postfix) with ESMTP id F422043C88;\n\tMon, 11 Mar 2024 15:47:30 +0100 (CET)", "from mails.dpdk.org (localhost [127.0.0.1])\n\tby mails.dpdk.org (Postfix) with ESMTP id 852474067B;\n\tMon, 11 Mar 2024 15:47:30 +0100 (CET)", "from foss.arm.com (foss.arm.com [217.140.110.172])\n by mails.dpdk.org (Postfix) with ESMTP id 95FBA4026B\n for <dev@dpdk.org>; Mon, 11 Mar 2024 15:47:29 +0100 (CET)", "from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14])\n by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id AF6B0FEC;\n Mon, 11 Mar 2024 07:48:05 -0700 (PDT)", "from ampere-altra-2-1.usa.Arm.com (ampere-altra-2-1.usa.arm.com\n [10.118.91.158])\n by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B100B3F762;\n Mon, 11 Mar 2024 07:47:28 -0700 (PDT)" ], "From": "Paul Szczepanek <paul.szczepanek@arm.com>", "To": "dev@dpdk.org", "Cc": "bruce.richardson@intel.com,\n\tPaul Szczepanek <paul.szczepanek@arm.com>", "Subject": "[PATCH v9 0/5] add pointer compression API", "Date": "Mon, 11 Mar 2024 14:47:01 +0000", "Message-Id": "<20240311144706.204831-1-paul.szczepanek@arm.com>", "X-Mailer": "git-send-email 2.25.1", "In-Reply-To": "<20230927150854.3670391-2-paul.szczepanek@arm.com>", "References": "<20230927150854.3670391-2-paul.szczepanek@arm.com>", "MIME-Version": "1.0", "Content-Transfer-Encoding": "8bit", "X-BeenThere": "dev@dpdk.org", "X-Mailman-Version": "2.1.29", "Precedence": "list", "List-Id": "DPDK patches and discussions <dev.dpdk.org>", "List-Unsubscribe": "<https://mails.dpdk.org/options/dev>,\n <mailto:dev-request@dpdk.org?subject=unsubscribe>", "List-Archive": "<http://mails.dpdk.org/archives/dev/>", "List-Post": "<mailto:dev@dpdk.org>", "List-Help": "<mailto:dev-request@dpdk.org?subject=help>", "List-Subscribe": "<https://mails.dpdk.org/listinfo/dev>,\n <mailto:dev-request@dpdk.org?subject=subscribe>", "Errors-To": "dev-bounces@dpdk.org" }, "content": "This patchset is proposing adding a new header only library\nwith utility functions that allow compression of arrays of pointers.\n\nSince this is a header only library a patch needed to be added to amend\nthe build system to allow adding libraries without source files.\n\nWhen passing caches full of pointers between threads, memory containing\nthe pointers is copied multiple times which is especially costly between\ncores. A compression method will allow us to shrink the memory size\ncopied.\n\nThe compression takes advantage of the fact that pointers are usually\nlocated in a limited memory region (like a mempool). We can compress them\nby converting them to offsets from a base memory address.\n\nOffsets can be stored in fewer bytes (dictated by the memory region size\nand alignment of the pointer). For example: an 8 byte aligned pointer\nwhich is part of a 32GB memory pool can be stored in 4 bytes. The API is\nvery generic and does not assume mempool pointers, any pointer can be\npassed in.\n\nCompression is based on few and fast operations and especially with vector\ninstructions leveraged creates minimal overhead.\n\nThe API accepts and returns arrays because the overhead means it only is\nworth it when done in bulk.\n\nTest is added that shows potential performance gain from compression. In\nthis test an array of pointers is passed through a ring between two cores.\nIt shows the gain which is dependent on the bulk operation size. In this\nsynthetic test run on ampere altra a substantial (up to 25%) performance\ngain is seen if done in bulk size larger than 32. At 32 it breaks even and\nlower sizes create a small (less than 5%) slowdown due to overhead.\n\nIn a more realistic mock application running the l3 forwarding dpdk\nexample that works in pipeline mode on two cores this translated into a\n~5% throughput increase on an ampere altra.\n\nv2:\n* addressed review comments (style, explanations and typos)\n* lowered bulk iterations closer to original numbers to keep runtime short\n* fixed pointer size warning on 32-bit arch\nv3:\n* added 16-bit versions of compression functions and tests\n* added documentation of these new utility functions in the EAL guide\nv4:\n* added unit test\n* fix bug in NEON implementation of 32-bit decompress\nv5:\n* disable NEON and SVE implementation on AARCH32 due to wrong pointer size\nv6:\n* added example usage to commit message of the initial commit\nv7:\n* rebase to remove clashing mailmap changes\nv8:\n* put ptr compress into its own library\n* add depends-on tag\n* remove copyright bumps\n* typos\nv9\n* added MAINTAINERS entries, release notes, doc indexes etc.\n* added patch for build system to allow header only library\n\nPaul Szczepanek (5):\n lib: allow libraries with no sources\n ptr_compress: add pointer compression library\n test: add pointer compress tests to ring perf test\n docs: add pointer compression guide\n test: add unit test for ptr compression\n\n MAINTAINERS | 6 +\n app/test/meson.build | 21 +-\n app/test/test_ptr_compress.c | 108 +++++++\n app/test/test_ring.h | 92 ++++++\n app/test/test_ring_perf.c | 352 ++++++++++++++-------\n doc/api/doxy-api-index.md | 1 +\n doc/api/doxy-api.conf.in | 1 +\n doc/guides/prog_guide/index.rst | 1 +\n doc/guides/prog_guide/ptr_compress_lib.rst | 142 +++++++++\n doc/guides/rel_notes/release_24_03.rst | 6 +\n lib/meson.build | 15 +\n lib/ptr_compress/meson.build | 4 +\n lib/ptr_compress/rte_ptr_compress.h | 266 ++++++++++++++++\n 13 files changed, 883 insertions(+), 132 deletions(-)\n create mode 100644 app/test/test_ptr_compress.c\n create mode 100644 doc/guides/prog_guide/ptr_compress_lib.rst\n create mode 100644 lib/ptr_compress/meson.build\n create mode 100644 lib/ptr_compress/rte_ptr_compress.h\n\n--\n2.25.1" }