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=-4.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 96474C433DB for ; Thu, 14 Jan 2021 19:22:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5744423B55 for ; Thu, 14 Jan 2021 19:22:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730018AbhANTWd (ORCPT ); Thu, 14 Jan 2021 14:22:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43676 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729921AbhANTWc (ORCPT ); Thu, 14 Jan 2021 14:22:32 -0500 Received: from mail-ej1-x635.google.com (mail-ej1-x635.google.com [IPv6:2a00:1450:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 615F1C061575 for ; Thu, 14 Jan 2021 11:21:52 -0800 (PST) Received: by mail-ej1-x635.google.com with SMTP id ga15so9884965ejb.4 for ; Thu, 14 Jan 2021 11:21:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=hJ4PbZRXWGKbnNFaGjb6sbAezL9+pJDA5n1ewEcRakw=; b=b9JJTPOrthVfyFbfmueN5xKP6jsW2O1dwykI3ofvYqnA/17z96hcmzg1VwdbLS0LEM cLK7067HCIDL3Tz3ewDachamz7UUuJWQFDeVSTcU1pIDrBb9DeQlNMGVPlMH6dPylM6L hVXzhPwxtxUYWJYTrwWNZVMzHfwU0Zvlsa5lKWvcvl0VQqM+CDo6yArtH2fe3JPymQxa l2YuKlQBM8UJ6oaDgLwgGHlkUUzMoqx5ipnqcZPwSKf7+ZH0aSs7mvbhWO75/R8OMBX7 yQdsrTg4rHRLbmlE1v0aeehMwMqX+LUWXvCZcAQhcMSvvrvZgPFmgXOThTK638Oq33xq KGSg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=hJ4PbZRXWGKbnNFaGjb6sbAezL9+pJDA5n1ewEcRakw=; b=DnSCCNg1YcicEyehaTom5S9F2i3T5C3xusQ5dCo+movhyZPufgbcXJOgJiYknDG5TE YiyrdA5XlQC5CJk4le/0M1ehyfzVmsSk6LqYSBPyVowgbpf9Q3cpGSfbjW7yF7UIE+iO 5lbCdUROBL2I0kdkQlFOU7TXsSoFkTrTJjvRYfHU3dH7iAcHkfw/3h8eRYNJ1aXANsq8 wOGMT9kZZ+K3mhEJMJ3Sdwznu/XBVnCDmvSJEDvezsAWnX2krV+eOGARAzPCg6G7/WB7 lAMdJzd0xU9m1w1JT397pY5qxiNPDjE+7dubzVzNfloeRTEb0+L6jgdrE5yyCsXBFCh+ jKuA== X-Gm-Message-State: AOAM533DpmfiHMNVCq07rjPtiuAGlGzZclW5y7GN7q1zYGIkv7cRYgVY eFiNwFxnwbFFkceXk/JKPck= X-Google-Smtp-Source: ABdhPJymSRUtSVJJhoQUpZwedJopflzkCpJOkUSDAw1HwbYgz6q2T//Gpwkn6qPjSq8EsINMfJs2Ow== X-Received: by 2002:a17:906:1b41:: with SMTP id p1mr3250203ejg.162.1610652111079; Thu, 14 Jan 2021 11:21:51 -0800 (PST) Received: from [192.168.1.11] ([213.57.108.142]) by smtp.gmail.com with ESMTPSA id v25sm2349174ejw.21.2021.01.14.11.21.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 14 Jan 2021 11:21:50 -0800 (PST) Subject: Re: [PATCH v1 net-next 00/15] nvme-tcp receive offloads To: David Ahern , Sagi Grimberg , Boris Pismenny , kuba@kernel.org, davem@davemloft.net, saeedm@nvidia.com, hch@lst.de, axboe@fb.com, kbusch@kernel.org, viro@zeniv.linux.org.uk, edumazet@google.com Cc: yorayz@nvidia.com, boris.pismenny@gmail.com, benishay@nvidia.com, linux-nvme@lists.infradead.org, netdev@vger.kernel.org, ogerlitz@nvidia.com References: <20201207210649.19194-1-borisp@mellanox.com> <69f9a7c3-e2ab-454a-2713-2e9c9dea4e47@grimberg.me> <967ae867-42c9-731d-9cb1-2c81fcc1ef77@gmail.com> From: Boris Pismenny Message-ID: Date: Thu, 14 Jan 2021 21:21:47 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: <967ae867-42c9-731d-9cb1-2c81fcc1ef77@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 14/01/2021 6:47, David Ahern wrote: > On 1/13/21 6:27 PM, Sagi Grimberg wrote: >>> Changes since RFC v1: >>> ========================================= >>> * Split mlx5 driver patches to several commits >>> * Fix nvme-tcp handling of recovery flows. In particular, move queue >>> offlaod >>>    init/teardown to the start/stop functions. >> >> I'm assuming that you tested controller resets and network hiccups >> during traffic right? > > I had questions on this part as well -- e.g., what happens on a TCP > retry? packets arrive, sgl filled for the command id, but packet is > dropped in the stack (e.g., enqueue backlog is filled, so packet gets > dropped) > On re-transmission the HW context's expected tcp sequence number doesn't match. As a result, the received packet is un-offloaded and software will do the copy/crc for its data. As a general rule, if HW context expected sequence numbers don't match, then there's no offload.