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=-4.2 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 76BE4C43462 for ; Wed, 19 May 2021 14:31:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 58A61613AA for ; Wed, 19 May 2021 14:31:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354270AbhESOdB (ORCPT ); Wed, 19 May 2021 10:33:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41590 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354148AbhESOcl (ORCPT ); Wed, 19 May 2021 10:32:41 -0400 Received: from mail-wr1-x431.google.com (mail-wr1-x431.google.com [IPv6:2a00:1450:4864:20::431]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5F78AC061342; Wed, 19 May 2021 07:31:15 -0700 (PDT) Received: by mail-wr1-x431.google.com with SMTP id v12so14260323wrq.6; Wed, 19 May 2021 07:31:15 -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=/uIuAty7PjxXFt4IM0i+V1A/dMXLvYisaqsv/qbrezE=; b=W+/COpqc5fQ8jmoquxbMKC6Ehnr83ZF2XRb52KqwZYN7L9L0nJoj8xNIabgDHYxZU0 F6iZlhockfTfVVlBkn4ud9d63iT87RLJhl0WQV+OQVc0Z9lsHJAAuhWChvkIKFxDEhLd Xoa9cvo6JnHyS6iHtnXsHKHp+ZdMGxHsp/sajjaTvDNFprJ9bSOJGFyOiuU3cfWjhy2C YskgE3TmZMU/r5Xd90LTUeyiE4CVC0A4tBp0aekOUo+UNVY56u8W9gQ6fkhcO9VfRGSx GzoIvK4VI42X9hGqwFgF2D24x6CNomcKUJUvFaU7WURaHypRYJQvhdgxRr44O6trhOlA fB2w== 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=/uIuAty7PjxXFt4IM0i+V1A/dMXLvYisaqsv/qbrezE=; b=OTKeX8ewGBBAefsl2ZM7+uk0IgoWihAVVH0uR2IHXDTN+91ccXgB3OAt1hWa80ZGrx m5Ta4wq5pZbd/wiz7NS2MPHbyTxc0ZnSiTAuoT3p8HFPmjzVmQ7eUy9e1ne58rDTpQWb GuO25X45RcSDWwxHodNOuft5/VWhDmL8CVgc4KzIWB9FIPRmoDJNzRQaA3jbZSt1r+7w SKyMNh48HLuXOhZGgyKpJ7BlC2Lu/JZjpO4gvaApLgGeQjatfJdddFNFu91a20xk/v3+ Zc7ulqr1BBtmcG2sqcq/OFuvxBW3MVYKayY9SywIq8+Vs9IFh9MASRPl7jSD6w/xPpGI N/Iw== X-Gm-Message-State: AOAM5305jymLU/upyPckTMHPiiApfhoPQpe7Tdgy19uvbMWwvNou4fGO zGVIEfvmrhNg//gQX3Y7n5NiFgvu5bQ= X-Google-Smtp-Source: ABdhPJyXuJnhzN0eu3ei8cGd0y+n4IYYl4B39s4zlfx5aYYQ7hSLjMfpxGTJMNX9DJK1bCo8vkyTLw== X-Received: by 2002:a5d:508e:: with SMTP id a14mr14900327wrt.88.1621434674015; Wed, 19 May 2021 07:31:14 -0700 (PDT) Received: from [10.0.0.2] ([37.172.163.196]) by smtp.gmail.com with ESMTPSA id c6sm7693369wru.50.2021.05.19.07.31.11 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 19 May 2021 07:31:12 -0700 (PDT) Subject: Re: [Bloat] virtio_net: BQL? To: Stephen Hemminger , Dave Taht Cc: Willem de Bruijn , "Michael S. Tsirkin" , Xianting Tian , Linux Kernel Network Developers , LKML , virtualization , bloat , Jakub Kicinski , "David S. Miller" References: <56270996-33a6-d71b-d935-452dad121df7@linux.alibaba.com> <20210517160036.4093d3f2@hermes.local> From: Eric Dumazet Message-ID: Date: Wed, 19 May 2021 16:31:10 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 In-Reply-To: <20210517160036.4093d3f2@hermes.local> 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 5/18/21 1:00 AM, Stephen Hemminger wrote: > > The Azure network driver (netvsc) also does not have BQL. Several years ago > I tried adding it but it benchmarked worse and there is the added complexity > of handling the accelerated networking VF path. > Note that NIC with many TX queues make BQL almost useless, only adding extra overhead. We should probably make BQL something that can be manually turned on/off.