From patchwork Fri Aug 19 12:19:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dylan Yudaken X-Patchwork-Id: 12948777 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5714C3F6B0 for ; Fri, 19 Aug 2022 12:20:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347929AbiHSMUh (ORCPT ); Fri, 19 Aug 2022 08:20:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53036 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348329AbiHSMUg (ORCPT ); Fri, 19 Aug 2022 08:20:36 -0400 Received: from mx0b-00082601.pphosted.com (mx0b-00082601.pphosted.com [67.231.153.30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A594100F28 for ; Fri, 19 Aug 2022 05:20:35 -0700 (PDT) Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 27JARC6m006347 for ; Fri, 19 Aug 2022 05:20:34 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=facebook; bh=CsrLWM7y1KdsIsop+YsRECG7/CmMqtPy7EzzIB4j1+A=; b=KMmw2drnaL2xjG56y4ikwIAvthehZhkv4pi6Cz3KxtnX89PRhWIeRPiAdeJnKJr550FZ mUJlHFATgoQPU4Ov5fJHhlMJ6b7El2fBEfp6czmmqn5ZCHTUT2hvzRjNGUvM2HBgajl4 e4zHOoE6xbeHK7pUJgXtI7Z/CFCWVmybtYs= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3j1jqgrmph-17 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 19 Aug 2022 05:20:34 -0700 Received: from twshared14074.07.ash9.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Fri, 19 Aug 2022 05:20:33 -0700 Received: by devbig038.lla2.facebook.com (Postfix, from userid 572232) id 79D494CEF042; Fri, 19 Aug 2022 05:20:25 -0700 (PDT) From: Dylan Yudaken To: Jens Axboe , Pavel Begunkov , CC: , Dylan Yudaken Subject: [PATCH for-next v3 0/7] io_uring: defer task work to when it is needed Date: Fri, 19 Aug 2022 05:19:39 -0700 Message-ID: <20220819121946.676065-1-dylany@fb.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: JqMa5XzmAwCyXqQ19YqrdADsyKv_eFv4 X-Proofpoint-GUID: JqMa5XzmAwCyXqQ19YqrdADsyKv_eFv4 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-08-19_06,2022-08-18_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org We have seen workloads which suffer due to the way task work is currently scheduled. This scheduling can cause non-trivial tasks to run interrupting useful work on the workload. For example in network servers, a large async recv may run, calling memcpy on a large packet, interrupting a send. Which would add latency. This series adds an option to defer async work until user space calls io_uring_enter with the GETEVENTS flag. This allows the workload to choose when to schedule async work and have finer control (at the expense of complexity of managing this) of scheduling. Patches 1,2 are prep patches Patch 3 changes io_uring_enter to not pre-run task work Patch 4/5/6 adds the new flag and functionality Patch 7 adds tracing for the local task work running Changes since v2: - add a patch to trace local task work run - return -EEXIST if calling from the wrong task - properly handle shutting down due to an exec - remove 'all' parameter from io_run_task_work_ctx Changes since v1: - Removed the first patch (using ctx variable) which was broken - Require IORING_SETUP_SINGLE_ISSUER and make sure waiter task is the same as the submitter task - Just don't run task work at the start of io_uring_enter (Pavel's suggestion) - Remove io_move_task_work_from_local - Fix locking bugs Dylan Yudaken (7): io_uring: remove unnecessary variable io_uring: introduce io_has_work io_uring: do not run task work at the start of io_uring_enter io_uring: add IORING_SETUP_DEFER_TASKRUN io_uring: move io_eventfd_put io_uring: signal registered eventfd to process deferred task work io_uring: trace local task work run include/linux/io_uring_types.h | 3 + include/trace/events/io_uring.h | 29 ++++ include/uapi/linux/io_uring.h | 7 + io_uring/cancel.c | 2 +- io_uring/io_uring.c | 264 ++++++++++++++++++++++++++------ io_uring/io_uring.h | 29 +++- io_uring/rsrc.c | 2 +- 7 files changed, 285 insertions(+), 51 deletions(-) base-commit: 5993000dc6b31b927403cee65fbc5f9f070fa3e4 prerequisite-patch-id: cb1d024945aa728d09a131156140a33d30bc268b Acked-by: Hao Xu