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 8CC3DC352A1 for ; Wed, 7 Dec 2022 18:53:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229694AbiLGSx5 (ORCPT ); Wed, 7 Dec 2022 13:53:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56666 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229449AbiLGSx4 (ORCPT ); Wed, 7 Dec 2022 13:53:56 -0500 Received: from mail-ed1-x52a.google.com (mail-ed1-x52a.google.com [IPv6:2a00:1450:4864:20::52a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61F8B49B42 for ; Wed, 7 Dec 2022 10:53:55 -0800 (PST) Received: by mail-ed1-x52a.google.com with SMTP id f7so26225690edc.6 for ; Wed, 07 Dec 2022 10:53:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=pGpz+Hdu80xBR9hqsOFKdws2bU8+HwauioGzpq47VV8=; b=pHyMqA4g/DBbLagxsO6LAub/N04bKJlv+M/6McQ2Jyax1Pl6nvyspC336mfcTgPlWl 7U2p4sEHMeCerRZczy4C9V3zgVsKoNT9pviwo9x2jYisTJGUY2FzUwoxw5qxdOXlhb+X /F2v374LPKP1pKGHOldbDUkROQQiya5nPqSczQf+4oRByaG7jceAy6wYSMfFFa7Pit38 k0DarmpaAtcKTKeEjv6qKJqGBVsN1lmjYHs3RZKtCdZRKrsycbZ8i20pKpvkFo/oSNW/ oIunNNFceE3DUaGAO6KpyA5AgRZcqhnS1EXdHWH0az/9ThwJMJGAbCTP6tEztESTlClY oP/A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=pGpz+Hdu80xBR9hqsOFKdws2bU8+HwauioGzpq47VV8=; b=hhq9bpC46CghFiMFwpXxDSQlafVb/iwopZ14tER3EukEuy+CNDwj56tHE8ZAMK2K0S ZbhwNWgOWfnpWmf1w42s87n4EQe3AF9WrVxJT8qEeWidJpQjrxwjvqxJrYoD+7J/jlYP 0bfx4xhKKERqo0tiNy/Iyu/8+Of403TnWen21WhHM/JB39sf+cE10Y8SfNWpEqwTmcHI 5KldbC5HJG78hTU3vzY0hdbi9Olw+xFLg5BoAPF3Iv/4B6Sa8CrGl8hyqJSQQJQl3i6n Rvj4ALu6qBq2qhXKNT92ciPYoMw23ZWNwzCSA5YrxEPRi9/JgY2pU8/SsmyTeNvesItZ 2MfA== X-Gm-Message-State: ANoB5pnkKdxEwGrQfQDr23qqxKQKXLRd1tHH/3JelxFshFkP26rdfR1w wZuDkRB6XdrM/yhzEt1BEVo= X-Google-Smtp-Source: AA0mqf743J8BOj2NlWY6idkS2IsT0ZAA1McokeBg681OvuObjbFqIOmHViisxhqqaK3x0vw0IG8t1w== X-Received: by 2002:aa7:d68d:0:b0:46a:e912:fbcd with SMTP id d13-20020aa7d68d000000b0046ae912fbcdmr46016309edr.378.1670439234003; Wed, 07 Dec 2022 10:53:54 -0800 (PST) Received: from [192.168.0.105] ([77.126.19.155]) by smtp.gmail.com with ESMTPSA id d18-20020a50fb12000000b004588ef795easm2552170edq.34.2022.12.07.10.53.52 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 07 Dec 2022 10:53:53 -0800 (PST) Message-ID: <7beeecae-8d6f-d4c2-db43-ddf468469ca0@gmail.com> Date: Wed, 7 Dec 2022 20:53:51 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: Re: [PATCH v2 net-next 2/3] net/mlx4: MLX4_TX_BOUNCE_BUFFER_SIZE depends on MAX_SKB_FRAGS Content-Language: en-US To: Eric Dumazet , "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: Tariq Toukan , Leon Romanovsky , netdev@vger.kernel.org, eric.dumazet@gmail.com, Wei Wang References: <20221207141237.2575012-1-edumazet@google.com> <20221207141237.2575012-3-edumazet@google.com> From: Tariq Toukan In-Reply-To: <20221207141237.2575012-3-edumazet@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 12/7/2022 4:12 PM, Eric Dumazet wrote: > Google production kernel has increased MAX_SKB_FRAGS to 45 > for BIG-TCP rollout. > > Unfortunately mlx4 TX bounce buffer is not big enough whenever > an skb has up to 45 page fragments. > > This can happen often with TCP TX zero copy, as one frag usually > holds 4096 bytes of payload (order-0 page). > > Tested: > Kernel built with MAX_SKB_FRAGS=45 > ip link set dev eth0 gso_max_size 185000 > netperf -t TCP_SENDFILE > > I made sure that "ethtool -G eth0 tx 64" was properly working, > ring->full_size being set to 15. > > Signed-off-by: Eric Dumazet > Reported-by: Wei Wang > Cc: Tariq Toukan Reviewed-by: Tariq Toukan