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GET /api/patches/116246/?format=api
{ "id": 116246, "url": "http://patches.dpdk.org/api/patches/116246/?format=api", "web_url": "http://patches.dpdk.org/project/dpdk/patch/20220913131941.582819-5-kevin.laatz@intel.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": "<20220913131941.582819-5-kevin.laatz@intel.com>", "list_archive_url": "https://inbox.dpdk.org/dev/20220913131941.582819-5-kevin.laatz@intel.com", "date": "2022-09-13T13:19:41", "name": "[v6,4/4] doc: add howto guide for lcore poll busyness", "commit_ref": null, "pull_url": null, "state": "superseded", "archived": true, "hash": "bc2d08177e68d300636348e2c0dd8735a5870433", "submitter": { "id": 921, "url": "http://patches.dpdk.org/api/people/921/?format=api", "name": "Kevin Laatz", "email": "kevin.laatz@intel.com" }, "delegate": { "id": 1, "url": "http://patches.dpdk.org/api/users/1/?format=api", "username": "tmonjalo", "first_name": "Thomas", "last_name": "Monjalon", "email": "thomas@monjalon.net" }, "mbox": "http://patches.dpdk.org/project/dpdk/patch/20220913131941.582819-5-kevin.laatz@intel.com/mbox/", "series": [ { "id": 24646, "url": "http://patches.dpdk.org/api/series/24646/?format=api", "web_url": "http://patches.dpdk.org/project/dpdk/list/?series=24646", "date": "2022-09-13T13:19:37", "name": "Add lcore poll busyness telemetry", "version": 6, "mbox": "http://patches.dpdk.org/series/24646/mbox/" } ], "comments": "http://patches.dpdk.org/api/patches/116246/comments/", "check": "success", "checks": "http://patches.dpdk.org/api/patches/116246/checks/", "tags": {}, "related": [], "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 5E112A0032;\n\tTue, 13 Sep 2022 15:17:04 +0200 (CEST)", "from [217.70.189.124] (localhost [127.0.0.1])\n\tby mails.dpdk.org (Postfix) with ESMTP id 526FC427F3;\n\tTue, 13 Sep 2022 15:17:04 +0200 (CEST)", "from mga11.intel.com (mga11.intel.com [192.55.52.93])\n by mails.dpdk.org (Postfix) with ESMTP id A3F84400D6\n for <dev@dpdk.org>; Tue, 13 Sep 2022 15:17:02 +0200 (CEST)", "from orsmga003.jf.intel.com ([10.7.209.27])\n by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384;\n 13 Sep 2022 06:16:37 -0700", "from silpixa00401122.ir.intel.com ([10.237.213.42])\n by orsmga003.jf.intel.com with ESMTP; 13 Sep 2022 06:16:36 -0700" ], "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple;\n d=intel.com; i=@intel.com; q=dns/txt; s=Intel;\n t=1663075022; x=1694611022;\n h=from:to:cc:subject:date:message-id:in-reply-to:\n references:mime-version:content-transfer-encoding;\n bh=CCYH84CxqxOBWravHGKI5REiL4NY4Mbar5gZrJDNNjQ=;\n b=PKy9xZOXz9nROixOdjQDO53fc9CbBXIHJ3436nBmKd/Cv3qCXVyb9Dup\n 0vushgwNnjjjCEu7xh1q44vzn19+hhtfjltu1NK9YlvGON3qi/TqPFROv\n PCJrbtVhSCGGh7bn0OLpjLuQh6k/s+rjonpwdJOnF/rs4mlg4csV2GMtK\n IlUNCOr1re5+/3rtPSSGtZWW4elr0ysfY+p8YaUp3euGLn7ECemHJFHsO\n lhIj+e7dfkFMDt9Tf2HuPN9GERCamN/5oYWJMxMqC3QnHZVvPXw6miMoI\n oipH2KElRahGAZzCS3RyV7vue/7E1K82/M7PQxt3RCR/DdNYiPHmfy3+Y w==;", "X-IronPort-AV": [ "E=McAfee;i=\"6500,9779,10468\"; a=\"295724499\"", "E=Sophos;i=\"5.93,312,1654585200\"; d=\"scan'208\";a=\"295724499\"", "E=Sophos;i=\"5.93,312,1654585200\"; d=\"scan'208\";a=\"567581202\"" ], "X-ExtLoop1": "1", "From": "Kevin Laatz <kevin.laatz@intel.com>", "To": "dev@dpdk.org", "Cc": "anatoly.burakov@intel.com,\n\tKevin Laatz <kevin.laatz@intel.com>", "Subject": "[PATCH v6 4/4] doc: add howto guide for lcore poll busyness", "Date": "Tue, 13 Sep 2022 14:19:41 +0100", "Message-Id": "<20220913131941.582819-5-kevin.laatz@intel.com>", "X-Mailer": "git-send-email 2.31.1", "In-Reply-To": "<20220913131941.582819-1-kevin.laatz@intel.com>", "References": "\n <24c49429394294cfbf0d9c506b205029bac77c8b.1657890378.git.anatoly.burakov@intel.com>\n <20220913131941.582819-1-kevin.laatz@intel.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": "Add a new section to the howto guides for using the new lcore poll\nbusyness telemetry endpoints and describe general usage.\n\nSigned-off-by: Kevin Laatz <kevin.laatz@intel.com>\n\n---\nv6:\n * Add mention of perf autotest in note mentioning perf impact.\n\nv4:\n * Include note on perf impact when the feature is enabled\n * Add doc to toctree\n * Updates to incorporate changes made earlier in the patchset\n\nv3:\n * Update naming to poll busyness\n---\n doc/guides/howto/index.rst | 1 +\n doc/guides/howto/lcore_poll_busyness.rst | 93 ++++++++++++++++++++++++\n 2 files changed, 94 insertions(+)\n create mode 100644 doc/guides/howto/lcore_poll_busyness.rst", "diff": "diff --git a/doc/guides/howto/index.rst b/doc/guides/howto/index.rst\nindex bf6337d021..0a9060c1d3 100644\n--- a/doc/guides/howto/index.rst\n+++ b/doc/guides/howto/index.rst\n@@ -21,3 +21,4 @@ HowTo Guides\n debug_troubleshoot\n openwrt\n avx512\n+ lcore_poll_busyness\ndiff --git a/doc/guides/howto/lcore_poll_busyness.rst b/doc/guides/howto/lcore_poll_busyness.rst\nnew file mode 100644\nindex 0000000000..be5ea2a85d\n--- /dev/null\n+++ b/doc/guides/howto/lcore_poll_busyness.rst\n@@ -0,0 +1,93 @@\n+.. SPDX-License-Identifier: BSD-3-Clause\n+ Copyright(c) 2022 Intel Corporation.\n+\n+Lcore Poll Busyness Telemetry\n+=============================\n+\n+The lcore poll busyness telemetry provides a built-in, generic method of gathering\n+lcore utilization metrics for running applications. These metrics are exposed\n+via a new telemetry endpoint.\n+\n+Since most DPDK APIs polling based, the poll busyness is calculated based on\n+APIs receiving 'work' (packets, completions, events, etc). Empty polls are\n+considered as idle, while non-empty polls are considered busy. Using the amount\n+of cycles spent processing empty polls, the busyness can be calculated and recorded.\n+\n+Application Specified Busyness\n+------------------------------\n+\n+Improved accuracy of the reported busyness may need more contextual awareness\n+from the application. For example, an application may make a number of calls to\n+rx_burst before processing packets. If the last burst was an \"empty poll\", then\n+the processing time of the packets would be falsely considered as \"idle\", since\n+the last burst was empty. The application should track if any of the polls\n+contained \"work\" to do and should mark the 'bulk' as \"busy\" cycles before\n+proceeding to the processesing. This type of awareness is only available within\n+the application.\n+\n+Applications can be modified to incorporate the extra contextual awareness in\n+order to improve the reported busyness by marking areas of code as \"busy\" or\n+\"idle\" appropriately. This can be done by inserting the timestamping macro::\n+\n+ RTE_LCORE_POLL_BUSYNESS_TIMESTAMP(0) /* to mark section as idle */\n+ RTE_LCORE_POLL_BUSYNESS_TIMESTAMP(32) /* where 32 is nb_pkts to mark section as busy (non-zero is busy) */\n+\n+All cycles since the last state change (idle to busy, or vice versa) will be\n+counted towards the current state's counter.\n+\n+Consuming the Telemetry\n+-----------------------\n+\n+The telemetry gathered for lcore poll busyness can be read from the `telemetry.py`\n+script via the new `/eal/lcore/poll_busyness` endpoint::\n+\n+ $ ./usertools/dpdk-telemetry.py\n+ --> /eal/lcore/poll_busyness\n+ {\"/eal/lcore/poll_busyness\": {\"12\": -1, \"13\": 85, \"14\": 84}}\n+\n+* Cores not collecting poll busyness will report \"-1\". E.g. control cores or inactive cores.\n+* All enabled cores will report their poll busyness in the range 0-100.\n+\n+Enabling and Disabling Lcore Poll Busyness Telemetry\n+----------------------------------------------------\n+\n+By default, the lcore poll busyness telemetry is disabled at compile time. In\n+order to allow DPDK to gather this metric, the ``enable_lcore_poll_busyness``\n+meson option must be set to ``true``.\n+\n+.. note::\n+ Enabling lcore poll busyness telemetry may impact performance due to the\n+ additional timestamping, potentially per poll depending on the application.\n+ This can be measured with the `lcore_poll_busyness_perf_autotest`.\n+\n+At compile time\n+^^^^^^^^^^^^^^^\n+\n+Support can be enabled/disabled at compile time via the meson option.\n+It is disabled by default.::\n+\n+ $ meson configure -Denable_lcore_poll_busyness=true #enable\n+\n+ $ meson configure -Denable_lcore_poll_busyness=false #disable\n+\n+At run time\n+^^^^^^^^^^^\n+\n+Support can also be enabled/disabled during runtime (if the meson option is\n+enabled at compile time). Disabling at runtime comes at the cost of an additional\n+branch, however no additional function calls are performed.\n+\n+To enable/disable support at runtime, a call can be made to the appropriately\n+telemetry endpoint.\n+\n+Disable::\n+\n+ $ ./usertools/dpdk-telemetry.py\n+ --> /eal/lcore/poll_busyness_disable\n+ {\"/eal/lcore/poll_busyness_disable\": {\"poll_busyness_enabled\": 0}}\n+\n+Enable::\n+\n+ $ ./usertools/dpdk-telemetry.py\n+ --> /eal/lcore/poll_busyness_enable\n+ {\"/eal/lcore/poll_busyness_enable\": {\"poll_busyness_enabled\": 1}}\n", "prefixes": [ "v6", "4/4" ] }