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=-5.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 3FF80C43603 for ; Sun, 15 Dec 2019 19:59:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 16B5A24679 for ; Sun, 15 Dec 2019 19:59:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="DYRm0n2d" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726481AbfLOT7q (ORCPT ); Sun, 15 Dec 2019 14:59:46 -0500 Received: from mail-pj1-f65.google.com ([209.85.216.65]:42581 "EHLO mail-pj1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726232AbfLOT7q (ORCPT ); Sun, 15 Dec 2019 14:59:46 -0500 Received: by mail-pj1-f65.google.com with SMTP id o11so2024502pjp.9 for ; Sun, 15 Dec 2019 11:59:45 -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=CyzEYO0tBZAuG9V1nNydZ2BB6jr/y6qEzG3L9J1ddi8=; b=DYRm0n2dZQjzZD2TexyuyXB23be06bctKnmRRPB1r5kMbOq2+i99kbqh/SpiDoG3x1 gIgit/Z3BobWG5xmah5F7yDbYKQkcvEfof5Zm39RBGfEO7YB0hH2LKsZPDqUF2LyD4Pu kOe5iwrZBKV20O6L/nneEz5tN72BnWsPPa4N4UUxKnyvvNSCQpdPOvDkGe89uHn9P/45 WrGTBD8Elnjt+MsylCtWuJHbNmiPx2oUHObr+pjzoN19nzxgAADFW3/Iw0pwEhxSDSzL LLDS7JS8AAsuLp2ItOsOqqisH1zG0/tP6B1mpliZNdtHWHfC41Pm2TI89u/t2IzBdfHx HeZQ== 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=CyzEYO0tBZAuG9V1nNydZ2BB6jr/y6qEzG3L9J1ddi8=; b=PPyh323bAXg8oymKdcGTXaARQnPsU4zq2+Zvzfv/l2ChihF01J2lQ0RThc6v628jAn 83PwAhlo4d2qySNLM/oLGZXMaLGawUB8HTDRAN6bru89q2lniWfh0VPxFtdjcAwW+z8W gnMhU61TAv/bgFKQEGjtcUEoHlJZ7MGLU/rZaL7jpRMMEJf8N716kLAdmZYfhrytWHZe AyImea4cziQAG/aV9BKWsF9TCo6l5a2Yvf5ayYl3Pv68YhJaRiRS0o/GdKlJlmhgpgRb 5I/LOgKRggOUToOng9yqtaVAdOFVU+viHiCR1dbTx6GcNVPl7FfWARWihu5fp5ZeQ8Pj WKpA== X-Gm-Message-State: APjAAAXmfUi3CzWvj60rSNN3g8eLssTNxic8AZCJ3w7Th2c+ZYdRPuF3 eJ5I1XA5c/yBuDreZvb6XQY= X-Google-Smtp-Source: APXvYqwElKNL2fwMJ1X3iQjEFXTurwtwovDXzea69dm4/hHdgyMNKZmC7QKZbXhIMgjIzzaBLUq/sA== X-Received: by 2002:a17:902:321:: with SMTP id 30mr12039769pld.153.1576439985369; Sun, 15 Dec 2019 11:59:45 -0800 (PST) Received: from [192.168.86.235] (c-73-241-150-58.hsd1.ca.comcast.net. [73.241.150.58]) by smtp.gmail.com with ESMTPSA id x4sm19097301pfx.68.2019.12.15.11.59.44 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 15 Dec 2019 11:59:44 -0800 (PST) Subject: Re: [PATCH net-next] tcp: Set rcv zerocopy hint correctly if skb last frag is < PAGE_SIZE. To: Jakub Kicinski , Arjun Roy Cc: davem@davemloft.net, netdev@vger.kernel.org, arjunroy@google.com, soheil@google.com, edumazet@google.com References: <20191212225930.233745-1-arjunroy.kdev@gmail.com> <20191215112214.3dd72168@cakuba.netronome.com> From: Eric Dumazet Message-ID: <80810ad7-a044-a88f-6032-0508661aadc2@gmail.com> Date: Sun, 15 Dec 2019 11:59:40 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20191215112214.3dd72168@cakuba.netronome.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 12/15/19 11:22 AM, Jakub Kicinski wrote: > On Thu, 12 Dec 2019 14:59:30 -0800, Arjun Roy wrote: >> At present, if the last frag of paged data in a skb has < PAGE_SIZE >> data, we compute the recv_skip_hint as being equal to the size of that >> frag and the entire next skb. >> >> Instead, just return the runt frag size as the hint. > > nit: this commit message doesn't really tell us why or what the effects > are going to be. Right, I added a bit of explanation. Basically we would hint the application to copy more bytes than needed. Since zerocopy is best effort, this can target net-next > >> Signed-off-by: Arjun Roy >> Acked-by: Soheil Hassas Yeganeh >> Signed-off-by: Eric Dumazet > > WARNING: Missing Signed-off-by: line by nominal patch author 'Arjun Roy ' > > You gotta send it from the same address you signed it off from. I sent a v2 on behalf of Arjun. Thanks.