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 67CDAECAAD3 for ; Mon, 5 Sep 2022 13:27:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237748AbiIEN1b (ORCPT ); Mon, 5 Sep 2022 09:27:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51528 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237738AbiIEN1a (ORCPT ); Mon, 5 Sep 2022 09:27:30 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 115CF4A112 for ; Mon, 5 Sep 2022 06:27:29 -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 284MVFAp022261 for ; Mon, 5 Sep 2022 06:27:28 -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=EK9NhxtaoyAmN4a9SiaR96Y291lR6GH5HqekGq5np2o=; b=QCgToWaIJ5gqkSIDihCTOchYpmaK1GGNTH4M8MLgX9jvz1Resunj924ql6iX3xY/p4PW hUObccwlkL0+n5Z6qOFR8L5xarjo+l3MWGok+OjH+5ICfLZFOw/GxJAE/6eWzyCUPZlB GA323sA3/GJldk6jC04tOKfya5T4tthKpr8= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3jcgaeegwy-15 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 05 Sep 2022 06:27:28 -0700 Received: from twshared14074.07.ash9.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:11d::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Mon, 5 Sep 2022 06:27:27 -0700 Received: by devbig038.lla2.facebook.com (Postfix, from userid 572232) id 434FD5AC5176; Mon, 5 Sep 2022 06:24:50 -0700 (PDT) From: Dylan Yudaken To: , CC: , , Dylan Yudaken Subject: [PATCH liburing v3 07/11] update io_uring_enter.2 docs for IORING_FEAT_NODROP Date: Mon, 5 Sep 2022 06:22:54 -0700 Message-ID: <20220905132258.1858915-8-dylany@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220905132258.1858915-1-dylany@fb.com> References: <20220905132258.1858915-1-dylany@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-ORIG-GUID: FBF-COkEVvzZPPGlheY3nNWk3yrT1xLk X-Proofpoint-GUID: FBF-COkEVvzZPPGlheY3nNWk3yrT1xLk 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=2022-09-05_09,2022-09-05_02,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org The EBUSY docs are out of date, so update them for the IORING_FEAT_NODROP feature flag Signed-off-by: Dylan Yudaken --- man/io_uring_enter.2 | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/man/io_uring_enter.2 b/man/io_uring_enter.2 index 1a9311e20357..4d8d488b5c1f 100644 --- a/man/io_uring_enter.2 +++ b/man/io_uring_enter.2 @@ -1330,7 +1330,18 @@ is a valid file descriptor, but the io_uring ring = is not in the right state for details on how to enable the ring. .TP .B EBUSY -The application is attempting to overcommit the number of requests it ca= n have +If the +.B IORING_FEAT_NODROP +feature flag is set, then +.B EBUSY +will be returned if there were overflow entries, +.B IORING_ENTER_GETEVENTS +flag is set and not all of the overflow entries were able to be flushed = to +the CQ ring. + +Without +.B IORING_FEAT_NODROP +the application is attempting to overcommit the number of requests it ca= n have pending. The application should wait for some completions and try again.= May occur if the application tries to queue more requests than we have room = for in the CQ ring, or if the application attempts to wait for more events with= out --=20 2.30.2