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 7C393C54EE9 for ; Thu, 1 Sep 2022 09:33:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233918AbiIAJdV (ORCPT ); Thu, 1 Sep 2022 05:33:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42686 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233751AbiIAJdR (ORCPT ); Thu, 1 Sep 2022 05:33:17 -0400 Received: from mx0b-00082601.pphosted.com (mx0b-00082601.pphosted.com [67.231.153.30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 62533133F0A for ; Thu, 1 Sep 2022 02:33:16 -0700 (PDT) Received: from pps.filterd (m0109332.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 2819Wfcv002750 for ; Thu, 1 Sep 2022 02:33:15 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=/dwzYe7skYYa7PtXqGvN3HFbnRJ0KJOIyWyVDMKn8H8=; b=B5ft57vzW5Byt6UZP522hQ/sMDQW87vkh1KsrYGy+9HLXCul9lz/oN8mH12iC5ICC1Aq ZbjG5NANtELpm8pMa2U4cuwkZYOhnlycAppW9jYo/4MS1L0e2aYZM+DneZstv/gOLmK5 FvnMA9tZL4gOrHC2RhinEoI7dg5DEOcNvrc= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3jat6s003c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 01 Sep 2022 02:33:15 -0700 Received: from twshared11415.03.ash7.facebook.com (2620:10d:c085:108::8) by mail.thefacebook.com (2620:10d:c085:21d::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 1 Sep 2022 02:33:13 -0700 Received: by devbig038.lla2.facebook.com (Postfix, from userid 572232) id A04D957693F2; Thu, 1 Sep 2022 02:33:06 -0700 (PDT) From: Dylan Yudaken To: Jens Axboe , Pavel Begunkov , CC: , Dylan Yudaken Subject: [PATCH liburing v2 02/12] Add documentation for IORING_SETUP_DEFER_TASKRUN flag Date: Thu, 1 Sep 2022 02:32:53 -0700 Message-ID: <20220901093303.1974274-3-dylany@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220901093303.1974274-1-dylany@fb.com> References: <20220901093303.1974274-1-dylany@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: an1GHmA0vd3PoR9XO4i4T9pkXKor6WpP X-Proofpoint-ORIG-GUID: an1GHmA0vd3PoR9XO4i4T9pkXKor6WpP 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=2022-09-01_06,2022-08-31_03,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Add man page entry to io_uring_setup.2 for the new flag Signed-off-by: Dylan Yudaken --- man/io_uring_setup.2 | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/man/io_uring_setup.2 b/man/io_uring_setup.2 index 32a9e2ee89b5..01eb70d95292 100644 --- a/man/io_uring_setup.2 +++ b/man/io_uring_setup.2 @@ -257,6 +257,25 @@ how many userspace tasks do .I io_uring_enter(2). Available since 5.20. +.TP +.B IORING_SETUP_DEFER_TASKRUN +By default, io_uring will process all outstanding work at the end of any= system +call or thread interrupt. This can delay the application from making oth= er progress. +Setting this flag will hint to io_uring that it should defer work until = an +.BR io_uring_enter(2) +call with the=20 +.B IORING_ENTER_GETEVENTS +flag set. This allows the application to request work to run just before= it wants to +process completions. +This flag requires the +.BR IORING_SETUP_SINGLE_ISSUER +flag to be set, and also enforces that the call to +.BR io_uring_enter(2) +is called from the same thread that submitted requests. +Note that if this flag is set then it is the application's responsibilit= y to periodically +trigger work (for example via any of the CQE waiting functions) or else = completions may +not be delivered. +Available since 6.1. .PP If no flags are specified, the io_uring instance is setup for interrupt driven I/O. I/O may be submitted using --=20 2.30.2