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 BDAAEC433FE for ; Thu, 21 Apr 2022 09:18:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1387524AbiDUJVB (ORCPT ); Thu, 21 Apr 2022 05:21:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1387511AbiDUJUv (ORCPT ); Thu, 21 Apr 2022 05:20:51 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C0482611F for ; Thu, 21 Apr 2022 02:18:02 -0700 (PDT) Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 23L7a8Dp008741 for ; Thu, 21 Apr 2022 02:18:02 -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=bJuM65BpJc63NMFO9/NkHf3pcltJlPS/DFBpKaOaQPk=; b=lldiBU3PAH0YDZFW6BV/8sBLbXKVgyuc09Zrbtl5fFGImHZmPvMjWaNqp0g3KqH11ADx MABcQ0/OTZhJaa8Vjgh3IxymUE/LJvujESgWdK0vR/fR1kh4gvkgj1O3qBTiup5AqoLJ J6BalZHxlbWkeB8zaU73UEZJwDFQ0sHfGGI= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3fj9p20w40-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 21 Apr 2022 02:18:02 -0700 Received: from twshared8053.07.ash9.facebook.com (2620:10d:c085:208::f) 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 15.1.2375.24; Thu, 21 Apr 2022 02:18:01 -0700 Received: by devbig039.lla1.facebook.com (Postfix, from userid 572232) id DC9A87CA771C; Thu, 21 Apr 2022 02:14:56 -0700 (PDT) From: Dylan Yudaken To: CC: , , , Dylan Yudaken Subject: [PATCH liburing 2/5] update io_uring_enter.2 docs for IORING_FEAT_NODROP Date: Thu, 21 Apr 2022 02:14:24 -0700 Message-ID: <20220421091427.2118151-3-dylany@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220421091427.2118151-1-dylany@fb.com> References: <20220421091427.2118151-1-dylany@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-ORIG-GUID: dWksx70JQy3sq0dI7Ptskcsw_Ehkgoha X-Proofpoint-GUID: dWksx70JQy3sq0dI7Ptskcsw_Ehkgoha X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.858,Hydra:6.0.486,FMLib:17.11.64.514 definitions=2022-04-20_06,2022-04-20_01,2022-02-23_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 22dbbd5..3112355 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 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=20 +.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