From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f171.google.com (mail-qk1-f171.google.com [209.85.222.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2F02F16D326 for ; Fri, 10 May 2024 11:11:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715339517; cv=none; b=OZU4FCu/tfcDJ29uiW0Ts1UrenBC1r781G98VuirIVzV6fDP2Vs/hWLJXVirRgiPSYa/7jzO5caiszmjfhGViYSQ1zPuSaEpdrQdExP8XHDGrPr6dZ2ZdIub5Ms9pegFPwPwU6tsbH7gLhbC8RwxCWQtW5yCeVGKcJ4b2sqmg3Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715339517; c=relaxed/simple; bh=yeo8sd8RFZdJ862z4TQug4Oieue2ymTOsLQYxEAdY08=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Rw7ljsT04RLQa22ODpzFQmo1+jhQf6J2uz3floC42V54tIPNzLiZyY4Tp2OR3ACZUaseG5CznpyU92nNos6ENvqHDjbJAu2Emoy9mWsS/yKKqqAeCe9y/S8AzCX+1GmQZuQYj16r2YwT1O0sSOYQ4acVOUccxAuTWnAlw+DIrY0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=resnulli.us; spf=none smtp.mailfrom=resnulli.us; dkim=pass (2048-bit key) header.d=resnulli-us.20230601.gappssmtp.com header.i=@resnulli-us.20230601.gappssmtp.com header.b=z3k5TqiZ; arc=none smtp.client-ip=209.85.222.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=resnulli.us Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=resnulli.us Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=resnulli-us.20230601.gappssmtp.com header.i=@resnulli-us.20230601.gappssmtp.com header.b="z3k5TqiZ" Received: by mail-qk1-f171.google.com with SMTP id af79cd13be357-792bd1f5b28so160802285a.2 for ; Fri, 10 May 2024 04:11:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=resnulli-us.20230601.gappssmtp.com; s=20230601; t=1715339515; x=1715944315; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=fzDowZL4O8ZaZ5oGwMtdLpyR1SKzWoUyd2n/48q61cY=; b=z3k5TqiZ0miLDhmtzMG6nni1qUmWge9059HmubHklBY5Wxeg8TC9dps77C7kgj4V44 ntYDclKXCAQYU6YB+LuqWFtdLFoXkvzgnU29Fq4rudFjd45PRcKbUiNq0fIStUVOFtB+ W1Qb8zufO6BJcSJmeOce8PKubKe5hLNM148vxJBGUWyw2GLK9/cvDgAoY5mkpurMn+hS OaSezFfaKwJ8RhYhfi8JPqHADeHl3MfJch9gk0RDWkW6iATV64EXh1vR4aeQzRBnNlpX vA1wMvkO/SsEcYw4pCkZB3GlqbcxNlDY7h5DukoNjYgNuHn9GRDeuvNFHz1i4ERnqKTE ZA9A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1715339515; x=1715944315; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=fzDowZL4O8ZaZ5oGwMtdLpyR1SKzWoUyd2n/48q61cY=; b=Zi35CHarXbvuHIPOkv5Xmu0Ui+yuG+PdPkttUNDvO1rh1wTjAm4oiaFCc2a7yASbdz OksLtv/RZrhMxwv4Qss+QcjCBEJJ2FregFjltjvlpKgoO50INVGASUf5TKImogm2CnpZ 0m/ogB3Yi47yiMDaPksyCMmefbYWK9DWPFPxuVbabsAtDGKIISuw5zriSLmaIoBWZz/z LQ8+0XbpDMJS/AKyBlLExyORfSV/4yT0vDsAR3LTF4WPS5iVgwGyUoKIsmhxcXfELU+K NCp9iupfE6y5NrwgQ3OZ/mRqi21xMVpgTxOmRTYH7S3ZP7FOMMSteNNoMowisOaXz2k/ h3Ng== X-Gm-Message-State: AOJu0YwcsCxwxZOg3UBUfMXpAVtuh3YrNyMDbZ/LVK8/CUO8eET9SdCA +/4hIP63t+oBuDehdxi0o9hyYh+WwMRKfHl8Z8489owcr7+Qx2auvPbVw7vMNM0= X-Google-Smtp-Source: AGHT+IHnhjG58jX47vVHtIqP3sRxriUOfdxV+WZjAFYtYRcjCXfosuwppdjvkX6oUiw2FmBIAynX9g== X-Received: by 2002:a05:620a:1003:b0:792:91ce:9b07 with SMTP id af79cd13be357-792c760083cmr219679285a.71.1715339514921; Fri, 10 May 2024 04:11:54 -0700 (PDT) Received: from localhost ([193.47.165.251]) by smtp.gmail.com with ESMTPSA id af79cd13be357-792bf310713sm168643085a.109.2024.05.10.04.11.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 May 2024 04:11:53 -0700 (PDT) Date: Fri, 10 May 2024 13:11:49 +0200 From: Jiri Pirko To: "Michael S. Tsirkin" Cc: netdev@vger.kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, jasowang@redhat.com, xuanzhuo@linux.alibaba.com, virtualization@lists.linux.dev, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com Subject: Re: [patch net-next] virtio_net: add support for Byte Queue Limits Message-ID: References: <20240509114615.317450-1-jiri@resnulli.us> <20240509084050-mutt-send-email-mst@kernel.org> <20240509102643-mutt-send-email-mst@kernel.org> <20240510065121-mutt-send-email-mst@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240510065121-mutt-send-email-mst@kernel.org> Fri, May 10, 2024 at 12:52:52PM CEST, mst@redhat.com wrote: >On Fri, May 10, 2024 at 12:37:15PM +0200, Jiri Pirko wrote: >> Thu, May 09, 2024 at 04:28:12PM CEST, mst@redhat.com wrote: >> >On Thu, May 09, 2024 at 03:31:56PM +0200, Jiri Pirko wrote: >> >> Thu, May 09, 2024 at 02:41:39PM CEST, mst@redhat.com wrote: >> >> >On Thu, May 09, 2024 at 01:46:15PM +0200, Jiri Pirko wrote: >> >> >> From: Jiri Pirko >> >> >> >> >> >> Add support for Byte Queue Limits (BQL). >> >> >> >> >> >> Signed-off-by: Jiri Pirko >> >> > >> >> >Can we get more detail on the benefits you observe etc? >> >> >Thanks! >> >> >> >> More info about the BQL in general is here: >> >> https://lwn.net/Articles/469652/ >> > >> >I know about BQL in general. We discussed BQL for virtio in the past >> >mostly I got the feedback from net core maintainers that it likely won't >> >benefit virtio. >> >> Do you have some link to that, or is it this thread: >> https://lore.kernel.org/netdev/21384cb5-99a6-7431-1039-b356521e1bc3@redhat.com/ > > >A quick search on lore turned up this, for example: >https://lore.kernel.org/all/a11eee78-b2a1-3dbc-4821-b5f4bfaae819@gmail.com/ Says: "Note that NIC with many TX queues make BQL almost useless, only adding extra overhead." But virtio can have one tx queue, I guess that could be quite common configuration in lot of deployments. > > > > >> I don't see why virtio should be any different from other >> drivers/devices that benefit from bql. HOL blocking is the same here are >> everywhere. >> >> > >> >So I'm asking, what kind of benefit do you observe? >> >> I don't have measurements at hand, will attach them to v2. >> >> Thanks! >> >> > >> >-- >> >MST >> > >