From mboxrd@z Thu Jan 1 00:00:00 1970 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 47A69C32773 for ; Tue, 16 Aug 2022 15:38:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236252AbiHPPi4 (ORCPT ); Tue, 16 Aug 2022 11:38:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51638 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236062AbiHPPiT (ORCPT ); Tue, 16 Aug 2022 11:38:19 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B6FD5C2 for ; Tue, 16 Aug 2022 08:37:46 -0700 (PDT) Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 27GBVjDs020558 for ; Tue, 16 Aug 2022 08:37:46 -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=V9yYoa+NokyIICc/7pE2jRpAh4BhT7xgCYmIfDozaCM=; b=Ucb7xmm/+7N/j6DcQxdeg9QlNchywuAsPXMhXj5RO3BvbZxB38zeeoiZjDQik+wAseOu 8pALWQGbd/BJ90FPQB+DaewJwy1u9tR+luMJcHr/l5+Zkf3BKvWvdn/bmuIABSQiZGOq FGjJ9qX94FSkINySFNwijFKBK1dzQVVwzX8= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3j0aek9kb9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 16 Aug 2022 08:37:46 -0700 Received: from twshared25684.07.ash9.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Tue, 16 Aug 2022 08:37:44 -0700 Received: by devbig038.lla2.facebook.com (Postfix, from userid 572232) id CD2614AAA7BE; Tue, 16 Aug 2022 08:37:38 -0700 (PDT) From: Dylan Yudaken To: Jens Axboe , Pavel Begunkov , CC: , Dylan Yudaken Subject: [PATCH for-next v2 0/6] io_uring: defer task work to when it is needed Date: Tue, 16 Aug 2022 08:37:22 -0700 Message-ID: <20220816153728.2160601-1-dylany@fb.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: xTQHOQBRraEi5R5izGpfxxqdDX9eKJ0S X-Proofpoint-ORIG-GUID: xTQHOQBRraEi5R5izGpfxxqdDX9eKJ0S X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-08-16_08,2022-08-16_02,2022-06-22_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 interruptin= g useful work on the workload. For example in network servers, a large asyn= c recv may run, calling memcpy on a large packet, interrupting a send. Whic= h 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 choos= e 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 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 (6): 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 include/linux/io_uring_types.h | 3 + include/uapi/linux/io_uring.h | 7 ++ io_uring/cancel.c | 2 +- io_uring/io_uring.c | 222 ++++++++++++++++++++++++++------- io_uring/io_uring.h | 30 ++++- io_uring/rsrc.c | 2 +- 6 files changed, 215 insertions(+), 51 deletions(-) base-commit: 5993000dc6b31b927403cee65fbc5f9f070fa3e4 prerequisite-patch-id: cb1d024945aa728d09a131156140a33d30bc268b --=20 2.30.2