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 X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B9BCC4338F for ; Thu, 12 Aug 2021 15:41:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7F15B60F91 for ; Thu, 12 Aug 2021 15:41:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237413AbhHLPmD (ORCPT ); Thu, 12 Aug 2021 11:42:03 -0400 Received: from mx0a-00069f02.pphosted.com ([205.220.165.32]:26590 "EHLO mx0a-00069f02.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238145AbhHLPmD (ORCPT ); Thu, 12 Aug 2021 11:42:03 -0400 Received: from pps.filterd (m0246617.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 17CFVxjJ030727; Thu, 12 Aug 2021 15:41:35 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : subject : date : message-id : mime-version : content-type : content-transfer-encoding; s=corp-2021-07-09; bh=EFEX6ngznciEgnqnlZweQ0XsRsaD+hm3C0eiw4KaFvY=; b=cris5ctgeUTvdu7yuCUbyfEomBaVYxNj4zr0y6b/q7dyWgbciYPCdiaeEESr3kb1DJve WRjtKP8zNyKWFmsOtMNSzlNKaJBgz8UDQtb0i9JIaPEuRyaNX/zWS8F/Uoyz+kDi8et1 vv8lGG/55Th8R0NaQsBGUBbaLO7+vjUO4MRutoPeWqhSKGnkm0/KSGzOQ002Bt8X+z5p 7e1Jy7slhMlH924EUUM2owvzghhrFwfyTs1CXJhYPa3r8y1GxurypRbsc82nadTWcesp ergpbDc4GWAnsB3EjjatpmK2nPJINUpN2s64/tpXLPXiaZOFXWwVJGQUQn+Rj/Nbz6XL SQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : subject : date : message-id : mime-version : content-type : content-transfer-encoding; s=corp-2020-01-29; bh=EFEX6ngznciEgnqnlZweQ0XsRsaD+hm3C0eiw4KaFvY=; b=n4QOGFLtV21sJs0lYXyDx6gdBPI0PNskzPvbwk0PF8exWpt4xxOdr+57sEbw0/EZBLIR htBeRjZdnqc7GbRcji4hRaTDAF3Wmi5lZYWXInbjga4k8xuR65JqGWFK+lG7S0t/vvgl 1tPo7kL3GRtqoSw9SiGrLwfqrdPAINYRUabAJoxuTDbQIONnzPH8V8IL0teYJa+g95aC MoIbyAX8yuksaCA0aB/lyBE8u2tWDd4eoHyBn8ojFl2eSxIWB3ixffty/yFymW9UlJI8 DYSha75lKV0JDK+9pxdjq/Ypz0MQpHMRE1HDwCcOghA4kd3dwCX+FcyubUIM+k7xo28I Xg== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by mx0b-00069f02.pphosted.com with ESMTP id 3ad2ajgnvk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 12 Aug 2021 15:41:35 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 17CFeTrH014663; Thu, 12 Aug 2021 15:41:34 GMT Received: from lab02.no.oracle.com (lab02.no.oracle.com [10.172.144.56]) by aserp3020.oracle.com with ESMTP id 3accrcbxf9-1; Thu, 12 Aug 2021 15:41:34 +0000 From: =?UTF-8?q?H=C3=A5kon=20Bugge?= To: Doug Ledford , Jason Gunthorpe , Leon Romanovsky , linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH for-next] RDMA/core/sa_query: Retry SA queries Date: Thu, 12 Aug 2021 17:41:31 +0200 Message-Id: <1628782891-26471-1-git-send-email-haakon.bugge@oracle.com> X-Mailer: git-send-email 1.8.3.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=10074 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 mlxlogscore=999 malwarescore=0 adultscore=0 spamscore=0 bulkscore=0 mlxscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2107140000 definitions=main-2108120101 X-Proofpoint-ORIG-GUID: HjNDw7QXfHCtOv7fjmjzImA9j-0Gjm07 X-Proofpoint-GUID: HjNDw7QXfHCtOv7fjmjzImA9j-0Gjm07 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org A MAD packet is sent as an unreliable datagram (UD). SA requests are sent as MAD packets. As such, SA requests or responses may be silently dropped. IB Core's MAD layer has a timeout and retry mechanism, which amongst other, is used by RDMA CM. But it is not used by SA queries. The lack of retries of SA queries leads to long specified timeout, and error being returned in case of packet loss. The ULP or user-land process has to perform the retry. Fix this by taking advantage of the MAD layer's retry mechanism. First, a check against a zero timeout is added in rdma_resolve_route(). In send_mad(), we set the MAD layer timeout to one tenth of the specified timeout and the number of retries to 10. The special case when timeout is less than 10 is handled. With this fix: # ucmatose -c 1000 -S 1024 -C 1 runs stable on an Infiniband fabric. Without this fix, we see an intermittent behavior and it errors out with: cmatose: event: RDMA_CM_EVENT_ROUTE_ERROR, error: -110 (110 is ETIMEDOUT) Fixes: f75b7a529494 ("[PATCH] IB: Add automatic retries to MAD layer") Signed-off-by: Håkon Bugge --- drivers/infiniband/core/cma.c | 3 +++ drivers/infiniband/core/sa_query.c | 9 ++++++++- 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index 515a7e9..bbcbab7 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -3117,6 +3117,9 @@ int rdma_resolve_route(struct rdma_cm_id *id, unsigned long timeout_ms) struct rdma_id_private *id_priv; int ret; + if (timeout_ms) + return -EINVAL; + id_priv = container_of(id, struct rdma_id_private, id); if (!cma_comp_exch(id_priv, RDMA_CM_ADDR_RESOLVED, RDMA_CM_ROUTE_QUERY)) return -EINVAL; diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c index b61576f..5a56082 100644 --- a/drivers/infiniband/core/sa_query.c +++ b/drivers/infiniband/core/sa_query.c @@ -1358,6 +1358,7 @@ static int send_mad(struct ib_sa_query *query, unsigned long timeout_ms, { unsigned long flags; int ret, id; + const int nmbr_sa_query_retries = 10; xa_lock_irqsave(&queries, flags); ret = __xa_alloc(&queries, &id, query, xa_limit_32b, gfp_mask); @@ -1365,7 +1366,13 @@ static int send_mad(struct ib_sa_query *query, unsigned long timeout_ms, if (ret < 0) return ret; - query->mad_buf->timeout_ms = timeout_ms; + query->mad_buf->timeout_ms = timeout_ms / nmbr_sa_query_retries; + query->mad_buf->retries = nmbr_sa_query_retries; + if (!query->mad_buf->timeout_ms) { + /* Special case, very small timeout_ms */ + query->mad_buf->timeout_ms = 1; + query->mad_buf->retries = timeout_ms; + } query->mad_buf->context[0] = query; query->id = id; -- 1.8.3.1