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 5E80EC433EF for ; Sat, 23 Apr 2022 01:54:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229455AbiDWB5v (ORCPT ); Fri, 22 Apr 2022 21:57:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37490 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231768AbiDWB5p (ORCPT ); Fri, 22 Apr 2022 21:57:45 -0400 Received: from mail-oi1-x22d.google.com (mail-oi1-x22d.google.com [IPv6:2607:f8b0:4864:20::22d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5CC07E4B for ; Fri, 22 Apr 2022 18:54:50 -0700 (PDT) Received: by mail-oi1-x22d.google.com with SMTP id t15so11010917oie.1 for ; Fri, 22 Apr 2022 18:54:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language :from:to:references:in-reply-to:content-transfer-encoding; bh=p7vjC567BURP8YKsIzj2NxBh4cGKgwagWxOhdvW3eo8=; b=cs5lsrjhx6QXVYkA9C8DrRm3BUjaXhH/jehrk2iCOsWmhICQeTUwNLEe6MiBKFV0XI pXy1G8Vd/yuDCSvl7+svjxmWJMoWV7OkO5ZfCwTA9fGTbE4pdJ9bL7pTMhyXkRFPIv+J Qw5NwDOCn6gJB9Wk+HiD/eYbm+WyiD/oAOtGBzTgaiZo2HL2qY/QVwl9Z19QlQRjHasY QHkjqge3HTnQmpOjk6Ng/Y38OH2H3JvHjqz2pmRtdwbkA9QfdcoROXxiU1lvRzX212ew pdbxAJtidsqxdtpVoM5l36EyqP9CCxPO1MVgsmYXMjrFxP6s4oNnECCjuBrp9wZUqNSh Braw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:from:to:references:in-reply-to :content-transfer-encoding; bh=p7vjC567BURP8YKsIzj2NxBh4cGKgwagWxOhdvW3eo8=; b=cD8Wqt2z1yF0zMmjdmhSo57TGlJk3K6ZsWvLBoc70DDAD5iSzhR8UwCkjhMiopGnJe umYqtdS2jFBH7mHRHw3hHhXl1qyHUx5ErMb/w6nRdW+oj5jg7Jvkt+BZqtGxfA4nVfdv E1btWfelnH9qvI2FyGerfML/yvBqdvms0GNzgzChaak5fvGBfjU8uuGvtPI74dLdh3TV jEATUQ0vbtzR2g+5P/a8Dvgf6om/8UcRZCY8wvb2nMhjDpxmw0Zv6mEEHopwqAW+ISV1 ed9yYrwkhP7WyavbfInLJ1CyMucCZwtm6jDEK9yuqrMTSA88hUSnQA5ocTbdeaWqZxBj EJgg== X-Gm-Message-State: AOAM532rNKbMBHIv/mXvYoxf6Ib5nIvpFEEoTQGnh/cyXMGyLHa4QDlT tOJ7wR9pV1Dk3E1qNXPoD/4= X-Google-Smtp-Source: ABdhPJxmOQfim2m0ldQSmihxqSoVS7m9W++gbY0Ukz5h5b8+gOeojVvjCFLqAlcKQ8fi1BQuoi3tiQ== X-Received: by 2002:a05:6808:17a3:b0:324:fcbf:3142 with SMTP id bg35-20020a05680817a300b00324fcbf3142mr1314494oib.5.1650678889752; Fri, 22 Apr 2022 18:54:49 -0700 (PDT) Received: from ?IPV6:2603:8081:140c:1a00:e508:94f4:5ee:8557? (2603-8081-140c-1a00-e508-94f4-05ee-8557.res6.spectrum.com. [2603:8081:140c:1a00:e508:94f4:5ee:8557]) by smtp.gmail.com with ESMTPSA id k15-20020a4a2a0f000000b0033a34a057c8sm1457554oof.11.2022.04.22.18.54.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 22 Apr 2022 18:54:49 -0700 (PDT) Message-ID: Date: Fri, 22 Apr 2022 20:54:48 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: bug report for rdma_rxe Content-Language: en-US From: Bob Pearson To: Jason Gunthorpe , Zhu Yanjun , "linux-rdma@vger.kernel.org" References: <5de7d1a9-a7ac-aea5-d11c-49423d3f0bf1@gmail.com> In-Reply-To: <5de7d1a9-a7ac-aea5-d11c-49423d3f0bf1@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On 4/22/22 16:04, Bob Pearson wrote: > Local operations in the rdma_rxe driver are not obviously idempotent. But, the > RC retry mechanism backs up the send queue to the point of the wqe that is > currently being acknowledged and re-walks the sq. Each send or write operation is > retried with the exception that the first one is truncated by the packets already > having been acknowledged. Each read and atomic operation is resent except that > read data already received in the first wqe is not requested. But all the > local operations are replayed. The problem is local invalidate which is destructive. > For example > > sq: some operation that times out > bind mw to mr > some other operation > invalidate mw > invalidate mr > > can't be replayed because invalidating the mr makes the second bind fail. > There are lots of other examples where things go wrong. > > To make things worse the send queue timer is never cleared and for typical > timeout values goes off every few msec whether anything actually failed. > > Bob This looks like an unholy mess. The reason I was looking at it is because Lustre on rxe doesn't work at the moment and the problems were traced to retry flows (on a very reliable network) caused by stray timeouts. We see local_invalidate_mr operations getting retried multiple times and not all of them succeed because the caller is remapping the fast MR in the mean time and changing the rkey. Bob