From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 70FD1138E for ; Mon, 6 Nov 2023 03:23:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=networkplumber-org.20230601.gappssmtp.com header.i=@networkplumber-org.20230601.gappssmtp.com header.b="IlEMqcXI" Received: from mail-pj1-x1032.google.com (mail-pj1-x1032.google.com [IPv6:2607:f8b0:4864:20::1032]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D24E0112 for ; Sun, 5 Nov 2023 19:23:11 -0800 (PST) Received: by mail-pj1-x1032.google.com with SMTP id 98e67ed59e1d1-28023eadc70so3235934a91.2 for ; Sun, 05 Nov 2023 19:23:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1699240991; x=1699845791; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=wh9fQ38uqWxfqKSp2NOqm3UoppKALypzJXvqmaMzdus=; b=IlEMqcXI0c47V67bbU33wktF5tYNAOMjf09o3E1n7rfmCmvJZhAhC7orcYx7wJCur0 MdpdwwmypAHkUE9QI/OJya1lsUVkI8dkbAFVLXAmfHqHoWv00sj4en6AYj4MfqtwAjPG ob83NXOut1E6KwJ8TgpZ6e56uB6hWTmyKQmjwGyli14kx8owIA7H+Wb+DJKwP8UkjQQN LTWCp+vwF9Nm9pTjVtZZ6Ya9CwwAaOA8hSahdsPGVZdCcmGDdvUIDGEuYV2ROF6I8axg 6DIQgbhSXzGZkKZPsGTSYgveboAjWpxb8J46bIni4w7+PtVqx/bgmsAPQimKyJB8nxIU 7qYw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699240991; x=1699845791; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=wh9fQ38uqWxfqKSp2NOqm3UoppKALypzJXvqmaMzdus=; b=scDiiKYOCmac2w9NbZp3bLTOMVqsRSUTcwG2/k/V/v+0nxOSd+BcnPVG/6OP+DkbkO volFhhs+s7N6gU+f8azu4LjOfEoquoFQ54Cp19xYO2dNAZMHf6YlMlnJbqq59w+jWrWN dw10IokMGHlpxOMpma/IAjLN385Vu1HedepRdCskdnzZm06vjmi/JSWs6HjKYUYowzSj obJgP5URC39ZBBX17XxcJ8Fd2NvpRmXifUuEKfN2EE/aI0cmZF+DWgISWc+1E3GJJeYR HPbkaHplJCT0LOMdde9qACZiLL37KvkTLqNMgTx4YdLAOLitlCzYoXj9d7OLM2lf8ZcF /miQ== X-Gm-Message-State: AOJu0YxCSCKZLBCeqIWiMKCcdVYz/QTmHZwAmTDpTK2q+1pBTK9tyfVm EHvw5ValB6M/1XG3teNVmmRGYA== X-Google-Smtp-Source: AGHT+IE12liFS3f22Ksa7SVPcpYz27eVsPPpKK9lLxjgXZ5jyt284l1QQjHweMQTJH1iqfKS8dckwg== X-Received: by 2002:a17:90b:38c6:b0:280:1af4:b519 with SMTP id nn6-20020a17090b38c600b002801af4b519mr17683108pjb.35.1699240991292; Sun, 05 Nov 2023 19:23:11 -0800 (PST) Received: from hermes.local (204-195-123-141.wavecable.com. [204.195.123.141]) by smtp.gmail.com with ESMTPSA id x6-20020a17090ab00600b00277560ecd5dsm4651385pjq.46.2023.11.05.19.23.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 05 Nov 2023 19:23:11 -0800 (PST) Date: Sun, 5 Nov 2023 19:23:09 -0800 From: Stephen Hemminger To: John Ousterhout Cc: Andrew Lunn , netdev@vger.kernel.org Subject: Re: Bypass qdiscs? Message-ID: <20231105192309.20416ff8@hermes.local> In-Reply-To: References: <29217dab-e00e-4e4c-8d6a-4088d8e79c8e@lunn.ch> 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-Transfer-Encoding: 7bit On Sat, 4 Nov 2023 19:47:30 -0700 John Ousterhout wrote: > I haven't tried creating a "pass through" qdisc, but that seems like a > reasonable approach if (as it seems) there isn't something already > built-in that provides equivalent functionality. > > -John- > > P.S. If hardware starts supporting Homa, I hope that it will be > possible to move the entire transport to the NIC, so that applications > can bypass the kernel entirely, as with RDMA. One old trick was setting netdev queue length to 0 to avoid qdisc.