From patchwork Mon Aug 15 13:09:43 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dylan Yudaken X-Patchwork-Id: 12943546 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 CB9BAC3F6B0 for ; Mon, 15 Aug 2022 13:15:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242823AbiHONPZ (ORCPT ); Mon, 15 Aug 2022 09:15:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242825AbiHONPQ (ORCPT ); Mon, 15 Aug 2022 09:15:16 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 66C99AA for ; Mon, 15 Aug 2022 06:15:14 -0700 (PDT) Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 27F9Oucg021310 for ; Mon, 15 Aug 2022 06:15:14 -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=geNmTpnjsOWYMRBUJxVvCYS4XuDc2QzfNx/AmkFBHp8=; b=N5TpzS3jfUEEcj/LoviAbBCzxTK1Nu6/rBD2He2rBg2C8S1HvfzDecfk1ufbZT+w/+e8 GtLJTDgUFB2sw8Fzgo3XYCYHDqf4VjpnaCqqN8VI5VymQ1KNwHSFlQ8b1pQ/uE0Z/fVN FQfGOiCD1gNNjbvgby2HHWzmA4iGezXMKNk= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3hykfy0x67-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 15 Aug 2022 06:15:14 -0700 Received: from twshared6324.05.ash7.facebook.com (2620:10d:c085:108::8) by mail.thefacebook.com (2620:10d:c085:11d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Mon, 15 Aug 2022 06:15:13 -0700 Received: by devbig038.lla2.facebook.com (Postfix, from userid 572232) id 4C0CA49B7303; Mon, 15 Aug 2022 06:09:55 -0700 (PDT) From: Dylan Yudaken To: Jens Axboe , Pavel Begunkov , CC: , Dylan Yudaken Subject: [PATCH liburing 07/11] update io_uring_enter.2 docs for IORING_FEAT_NODROP Date: Mon, 15 Aug 2022 06:09:43 -0700 Message-ID: <20220815130947.1002152-8-dylany@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220815130947.1002152-1-dylany@fb.com> References: <20220815130947.1002152-1-dylany@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: omJB7LsFtjthKxVPmtNfBdsBtDoMS6XX X-Proofpoint-ORIG-GUID: omJB7LsFtjthKxVPmtNfBdsBtDoMS6XX 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=2022-08-15_08,2022-08-15_01,2022-06-22_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 6e3ffa0f5ba8..9ad6349b2c4a 100644 --- a/man/io_uring_enter.2 +++ b/man/io_uring_enter.2 @@ -1327,7 +1327,18 @@ 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 can 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 can 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 without