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{ "id": 248, "url": "http://patches.dpdk.org/api/covers/248/?format=api", "web_url": "http://patches.dpdk.org/project/dpdk/cover/20231011124328.4002766-1-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": "<20231011124328.4002766-1-paul.szczepanek@arm.com>", "list_archive_url": "https://inbox.dpdk.org/dev/20231011124328.4002766-1-paul.szczepanek@arm.com", "date": "2023-10-11T12:43:26", "name": "[RFC,v2,0/2] 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/20231011124328.4002766-1-paul.szczepanek@arm.com/mbox/", "series": [ { "id": 29818, "url": "http://patches.dpdk.org/api/series/29818/?format=api", "web_url": "http://patches.dpdk.org/project/dpdk/list/?series=29818", "date": "2023-10-11T12:43:26", "name": "add pointer compression API", "version": 2, "mbox": "http://patches.dpdk.org/series/29818/mbox/" } ], "comments": "http://patches.dpdk.org/api/covers/248/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 3486642361;\n\tWed, 11 Oct 2023 14:44:50 +0200 (CEST)", "from mails.dpdk.org (localhost [127.0.0.1])\n\tby mails.dpdk.org (Postfix) with ESMTP id 22E7B40648;\n\tWed, 11 Oct 2023 14:44:50 +0200 (CEST)", "from foss.arm.com (foss.arm.com [217.140.110.172])\n by mails.dpdk.org (Postfix) with ESMTP id AF9FD40266\n for <dev@dpdk.org>; Wed, 11 Oct 2023 14:44:48 +0200 (CEST)", "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 EBCB5C15;\n Wed, 11 Oct 2023 05:45:28 -0700 (PDT)", "from ampere-altra-2-2.usa.Arm.com (unknown [10.118.91.160])\n by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 2FE6D3F5A1;\n Wed, 11 Oct 2023 05:44:48 -0700 (PDT)" ], "From": "Paul Szczepanek <paul.szczepanek@arm.com>", "To": "dev@dpdk.org", "Cc": "Paul Szczepanek <paul.szczepanek@arm.com>", "Subject": "[RFC v2 0/2] add pointer compression API", "Date": "Wed, 11 Oct 2023 12:43:26 +0000", "Message-Id": "<20231011124328.4002766-1-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 EAL header with utility functions\nthat allow compression of arrays of pointers.\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 this translated into a ~5% throughput\nincrease 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\n\nPaul Szczepanek (2):\n eal: add pointer compression functions\n test: add pointer compress tests to ring perf test\n\n .mailmap | 1 +\n app/test/test_ring.h | 59 +++++-\n app/test/test_ring_perf.c | 324 ++++++++++++++++++-----------\n lib/eal/include/meson.build | 1 +\n lib/eal/include/rte_ptr_compress.h | 160 ++++++++++++++\n 5 files changed, 421 insertions(+), 124 deletions(-)\n create mode 100644 lib/eal/include/rte_ptr_compress.h" }