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 9D152C6377D for ; Thu, 22 Jul 2021 14:03:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 73F9F6128D for ; Thu, 22 Jul 2021 14:03:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232260AbhGVNWa (ORCPT ); Thu, 22 Jul 2021 09:22:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39396 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232177AbhGVNW3 (ORCPT ); Thu, 22 Jul 2021 09:22:29 -0400 Received: from mail-ed1-x533.google.com (mail-ed1-x533.google.com [IPv6:2a00:1450:4864:20::533]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B07A1C061757 for ; Thu, 22 Jul 2021 07:03:03 -0700 (PDT) Received: by mail-ed1-x533.google.com with SMTP id ee25so6945503edb.5 for ; Thu, 22 Jul 2021 07:03:03 -0700 (PDT) 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=JInVbMJ39rRbjSmp4L7SQNWHFz2ZWJnf919ts/n3e20=; b=TEfYm2zsec0xSajEc6hyXS2+DKfnF3FjGyPcOt2vhkHSZBEmGRRZ+cMJjbc8dPmWIP 8gXYDEDlS0HrTw/jHDzS8f6VYY4uNfyQIRs9fZnuiG49+GfXQHG2W6rVmMveYc6UxPeB 0GFDxBsPsk3sYQNmLDnOlMCzCcWT7krkMXko1r1rfoZSZO8jPD8/8edNkbR9nhS/h078 4I8WW71NhKsLRqmsdrYsSh/yTbzu6pXIunABxuIC7q1+U2sfXlpuHo02vPh6sBZcv+Xn wSoIPGDOxa1MZ0HWcHYP7nUmsaS8hkj6sRTeWUNRIr+ygqpAUatV/Nue4LSlU484T4AQ 7jLQ== 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=JInVbMJ39rRbjSmp4L7SQNWHFz2ZWJnf919ts/n3e20=; b=P2moUQR2VGQK3bATaWMGzgk82mkgxfV2CDUHUk8JApeYxwLDe2FinS6Inzu/BvqEpE 1RCWpka8DasCHqThwov3UwVNkynN7W3e1xJbglyWjmep2jx6rMC9Msh5Ls45WAz2RFmD 7KshncTeouiyCwhjyw1AoTGmpdTCdqXe9MRBF2LUiBe4gsaGdBuBm5aNtUoKGcSKTePk muKh4KK7n+cPc3VkAZTOUen2p6tL6vr6qGS9vnKmOLWcab8+KQbM5v7kCBkUvYP57z9d BRPBhZjGLBOHZd7P3HOdB1nO/o/wXey4UgzJv+gL7ja3K1t5zaR0iNq25c4YSrjzxsfK 644w== X-Gm-Message-State: AOAM533ir9nAdFeXq7GaXsx50m1Kf9V2b9uNgHlA8q2f6pYZLcRjkygC aPhMHQqFMT+lGwAKGsYRXE4= X-Google-Smtp-Source: ABdhPJzY/6unCfvzdaw4EnuqzLvgNJGgvHE9sBOh5pPBCKOjzCHjOCGuHQ+q5D/4sC1kvOLv4gJ/Fg== X-Received: by 2002:a05:6402:615:: with SMTP id n21mr55763839edv.139.1626962582389; Thu, 22 Jul 2021 07:03:02 -0700 (PDT) Received: from [132.68.43.152] ([132.68.43.152]) by smtp.gmail.com with ESMTPSA id qp12sm9547732ejb.90.2021.07.22.07.02.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 22 Jul 2021 07:03:01 -0700 (PDT) Subject: Re: [PATCH v5 net-next 01/36] net: Introduce direct data placement tcp offload To: Eric Dumazet Cc: Boris Pismenny , David Ahern , Jakub Kicinski , David Miller , Saeed Mahameed , Christoph Hellwig , sagi@grimberg.me, axboe@fb.com, kbusch@kernel.org, Al Viro , smalin@marvell.com, boris.pismenny@gmail.com, linux-nvme@lists.infradead.org, netdev , benishay@nvidia.com, ogerlitz@nvidia.com, yorayz@nvidia.com, Boris Pismenny , Ben Ben-Ishay , Or Gerlitz , Yoray Zack References: <20210722110325.371-1-borisp@nvidia.com> <20210722110325.371-2-borisp@nvidia.com> <7fdb948a-6411-fce5-370f-90567d2fe985@gmail.com> From: Boris Pismenny Message-ID: Date: Thu, 22 Jul 2021 17:02:58 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 22/07/2021 16:39, Eric Dumazet wrote: > On Thu, Jul 22, 2021 at 3:33 PM Boris Pismenny wrote: > >> Sorry. My response above was about skb_condense which I've confused with >> tcp_collapse. >> >> In tcp_collapse, we could allow the copy, but the problem is CRC, which >> like TLS's skb->decrypted marks that the data passed the digest >> validation in the NIC. If we allow collapsing SKBs with mixed marks, we >> will need to force software copy+crc verification. As TCP collapse is >> indeed rare and the offload is opportunistic in nature, we can make this >> change and submit another version, but I'm confused; why was it OK for >> TLS, while it is not OK for DDP+CRC? >> > > Ah.... I guess I was focused on the DDP part, while all your changes > are really about the CRC part. > > Perhaps having an accessor to express the CRC status (and not be > confused by the DDP part) > could help the intent of the code. > An accessor function sounds like a great idea for readability, thanks Eric! We will re-spin the series and add it to v6.