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{ "id": 69782, "url": "http://patchwork.dpdk.org/api/covers/69782/?format=api", "web_url": "http://patchwork.dpdk.org/project/dpdk/cover/20200505211732.25291-1-honnappa.nagarahalli@arm.com/", "project": { "id": 1, "url": "http://patchwork.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": "<20200505211732.25291-1-honnappa.nagarahalli@arm.com>", "list_archive_url": "https://inbox.dpdk.org/dev/20200505211732.25291-1-honnappa.nagarahalli@arm.com", "date": "2020-05-05T21:17:26", "name": "[v4,0/6] use c11 atomics for service core lib", "submitter": { "id": 1045, "url": "http://patchwork.dpdk.org/api/people/1045/?format=api", "name": "Honnappa Nagarahalli", "email": "honnappa.nagarahalli@arm.com" }, "mbox": "http://patchwork.dpdk.org/project/dpdk/cover/20200505211732.25291-1-honnappa.nagarahalli@arm.com/mbox/", "series": [ { "id": 9845, "url": "http://patchwork.dpdk.org/api/series/9845/?format=api", "web_url": "http://patchwork.dpdk.org/project/dpdk/list/?series=9845", "date": "2020-05-05T21:17:26", "name": "use c11 atomics for service core lib", "version": 4, "mbox": "http://patchwork.dpdk.org/series/9845/mbox/" } ], "comments": "http://patchwork.dpdk.org/api/covers/69782/comments/", "headers": { "Return-Path": "<dev-bounces@dpdk.org>", "X-Original-To": "patchwork@inbox.dpdk.org", "Delivered-To": "patchwork@inbox.dpdk.org", "Received": [ "from dpdk.org (dpdk.org [92.243.14.124])\n\tby inbox.dpdk.org (Postfix) with ESMTP id 3445AA0352;\n\tTue, 5 May 2020 23:17:48 +0200 (CEST)", "from [92.243.14.124] (localhost [127.0.0.1])\n\tby dpdk.org (Postfix) with ESMTP id D4C801D67E;\n\tTue, 5 May 2020 23:17:47 +0200 (CEST)", "from foss.arm.com (foss.arm.com [217.140.110.172])\n by dpdk.org (Postfix) with ESMTP id F398D1D658\n for <dev@dpdk.org>; Tue, 5 May 2020 23:17:46 +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 65B3630E;\n Tue, 5 May 2020 14:17:46 -0700 (PDT)", "from qc2400f-1.austin.arm.com (qc2400f-1.austin.arm.com\n [10.118.14.48])\n by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5271D3F305;\n Tue, 5 May 2020 14:17:46 -0700 (PDT)" ], "From": "Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>", "To": "dev@dpdk.org,\n\tphil.yang@arm.com,\n\tharry.van.haaren@intel.com", "Cc": "thomas@monjalon.net, david.marchand@redhat.com,\n konstantin.ananyev@intel.com, jerinj@marvell.com, hemant.agrawal@nxp.com,\n gage.eads@intel.com, bruce.richardson@intel.com,\n honnappa.nagarahalli@arm.com, nd@arm.com", "Date": "Tue, 5 May 2020 16:17:26 -0500", "Message-Id": "<20200505211732.25291-1-honnappa.nagarahalli@arm.com>", "X-Mailer": "git-send-email 2.17.1", "In-Reply-To": "<1587659482-27133-1-git-send-email-phil.yang@arm.com>", "References": "<1587659482-27133-1-git-send-email-phil.yang@arm.com>", "Subject": "[dpdk-dev] [PATCH v4 0/6] use c11 atomics for service core lib", "X-BeenThere": "dev@dpdk.org", "X-Mailman-Version": "2.1.15", "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", "Sender": "\"dev\" <dev-bounces@dpdk.org>" }, "content": "The rte_atomic ops and rte_smp barriers enforce DMB barriers on aarch64.\nUsing c11 atomics with explicit memory ordering instead of the rte_atomic\nops and rte_smp barriers for inter-threads synchronization can uplift the\nperformance on aarch64 and no performance loss on x86.\n\nThis patchset contains:\n1) fix race condition for MT unsafe service.\n2) clean up redundant code.\n3) use c11 atomics for service core lib to avoid unnecessary barriers.\n\nv2:\nStill waiting on Harry for the final solution on the MT unsafe race\ncondition issue. But I have incorporated the comments so far.\n1. add 'Fixes' tag for bug-fix patches.\n2. remove 'Fixes' tag for code cleanup patches.\n3. remove unused parameter for service_dump_one function.\n4. replace the execute_lock atomic CAS operation to spinlock_try_lock.\n5. use c11 atomics with RELAXED memory ordering for num_mapped_cores.\n6. relax barriers for guard variables runstate, comp_runstate and\n app_runstate with c11 one-way barriers.\n\nv3:\nSending this version since Phil is on holiday.\n1. Updated the API documentation to indicate how the locking\n can be avoided.\n\nv4:\n1. Fix the nits in 2/6 commit message and comments in code.\n\nHonnappa Nagarahalli (2):\n service: fix race condition for MT unsafe service\n service: fix identification of service running on other lcore\n\nPhil Yang (4):\n service: remove rte prefix from static functions\n service: remove redundant code\n service: optimize with c11 atomics\n service: relax barriers with C11 atomics\n\n lib/librte_eal/common/rte_service.c | 234 ++++++++++--------\n lib/librte_eal/include/rte_service.h | 8 +-\n .../include/rte_service_component.h | 6 +-\n lib/librte_eal/meson.build | 4 +\n 4 files changed, 141 insertions(+), 111 deletions(-)" }