From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-x535.google.com (mail-pg1-x535.google.com [IPv6:2607:f8b0:4864:20::535]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 53AF23B29E for ; Fri, 25 Oct 2024 17:02:33 -0400 (EDT) Received: by mail-pg1-x535.google.com with SMTP id 41be03b00d2f7-7db908c9c83so1560651a12.2 for ; Fri, 25 Oct 2024 14:02:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1729890152; x=1730494952; darn=lists.bufferbloat.net; 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=znqHtE5JFtHMLtg8tR4QrWS5ZnRULPM/Jr+xHxLbPbY=; b=WPcoqOPYu76mpANYptgMjGzYUq8UPXIte9oyRwjoj/K9/7mrIz9MirbnnKeIGvvq1V MrIdbj89tMNKzNYOT5TzwoNb6kYAoyV8d4E3ZU7FwMm/hExHwq80qpO/gsdu9NYaKNnE 06A7F7QKh9+ZIMWr9PhNmcL1KCGjD7hBtscLfyAJFlmeCnUqnitsZWp3JkILgCEAS8p8 geyEbmh6yaN6CuavyGSdy0hDkmSPvDkL4njNJIa2SvOVL4sLlvjCCW7IENbSFgssWahe hb/oCbd4FyXXoLwLXEkpFmFLC3WKS9AVrcC0Lm69HNcfDWUGyeNL+fEeH2aDAe9xt+Ab EWdQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1729890152; x=1730494952; 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=znqHtE5JFtHMLtg8tR4QrWS5ZnRULPM/Jr+xHxLbPbY=; b=pduHWPiNPdfcNeoKWItfNVL/5on+4cOP+OAvl1+BlMCmxpkAN61lLoMqgY1zFwix0g KE6MefaHIxyp2JFCVr8Y3HKQABoZyI+l6/f0o22P654spcuFyie+M6NwIsQWVN9K2HNs 01FD3kWZheggq5VmRcaDyibKYkspZPWVWzhV1A+Ok6ROF2phTkZugrlkUI90oz0gArNZ gYaqlrlXUFS6vAuMwg4wqyMpkocHi1e7mqzEQMpqtxRHT1NOI0HbKiCPCuHg0atpN1f4 zifdV3LYpNkSN2VJV6fhuF8UDLZEnRqtwpv/1Hs2RMdfAr9fKhIXFZeqSZciMcXYvcaH 0Ikg== X-Gm-Message-State: AOJu0YynR3thxTHLXVqtIU6tv8MLIaqL+eGmCFBrrQ7/Sw9q8ZJZUJCW iskJU4qOxRFfNZPCJAOuA5qNmP/eO7h08FcdXv134BOgZ66CSYqO+RIPM0Rb9Ts7QownT5Hf1Ja v X-Google-Smtp-Source: AGHT+IFcAAHpzo1A/9TUPkuDLQhdqPsLWTV//GlnpbLxnBkp5tLMucycmrt150Y/O3/noOsB3HRF1Q== X-Received: by 2002:a17:90a:9cf:b0:2e2:b922:48a with SMTP id 98e67ed59e1d1-2e8f10723bdmr836470a91.18.1729890152436; Fri, 25 Oct 2024 14:02:32 -0700 (PDT) Received: from hermes.local (204-195-96-226.wavecable.com. [204.195.96.226]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-7edc8696918sm1532767a12.48.2024.10.25.14.02.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 25 Oct 2024 14:02:32 -0700 (PDT) Date: Fri, 25 Oct 2024 14:02:30 -0700 From: Stephen Hemminger To: Maximilian Bachl via Bloat Message-ID: <20241025140230.5b1263b8@hermes.local> In-Reply-To: References: <98eeb4b3-a8f8-4875-b021-aab0d5336959@fau.de> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Bloat] The NetEm qdisc does not work in conjunction with other qdiscs X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 25 Oct 2024 21:02:33 -0000 On Fri, 25 Oct 2024 21:55:21 +0200 Maximilian Bachl via Bloat wrote: > From my experience (experimented with it last year), it still behaves > weirdly. You can use htb for the shaping and you can create delay using > netem by using it on another (virtual) host on a link that does not have > any other qdiscs and where the link is not the bottleneck. > > Best regards, > Max Yes, netem has expectations about how inner qdisc behaves, and other qdisc used as inner have expectations about how/when packets are sent. There is a mismatch, not sure if it is fixable with in the architecture of how Linux queue disciplines operate. The best way is to use netem on an intermediate hop and not expect it to work perfectly when used on an endpoint. The same is true of Dummynet and other network emulators; they are uses as man-in-the-middle systems.