From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-x234.google.com (mail-qk0-x234.google.com [IPv6:2607:f8b0:400d:c09::234]) (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 7D5B93BA8E for ; Fri, 3 Mar 2017 09:23:33 -0500 (EST) Received: by mail-qk0-x234.google.com with SMTP id h9so23251020qke.2 for ; Fri, 03 Mar 2017 06:23:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=+zr1Zf52iS0fuG/dEADaIe82Oby+Fwn0/n6MQQsI/nQ=; b=G3XsOT8FdYgm7mKhOLOTT/sheN2YP/yQ2L6MxZlvkpdNbKgQ8ZD0aj853YzWShcdw8 rR+FZ0MI9EraHFxwQuRiaoGp5ofjm4Dz8eh1ImfGUcY/6VjTe++4gVdtO+2a3q5dOzZk /Gge0Ljy/oO1nkePRMp48c5Id/w9I2CCWL+YPj4EzJ+OFMc6RVM8zeZ+2eBpXJ339Jeb 1gWnCJ846bscBZORA6ajgEVctYQU+EW+KCDk413chZEul2MEkeKvDehFtfIsoQNt1nO1 xTgVFSkt1cU3ePK3s3t/zCbJapV1FsYwcp+WL1hCCQZRkRcfADK6EuU1mG9iuMma4+Dr Joow== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=+zr1Zf52iS0fuG/dEADaIe82Oby+Fwn0/n6MQQsI/nQ=; b=Apj9vsiQdXJH1bmAV0YoH58+E4Xi79gFpuiFBp/XahdiWu//OlrEWQNan06+xJ10Ji LwIy/rGDVJlyQUfu4ASQ14PzT8hIDlx4klivV03AIWBJLQbF1MaXQnoXwmTLLBATyC4x lXiiT48Sy8TcA8mpnEESustMfyvTSJN1FjLVgEqxYEd43u55cPO5vh1vYby7Okhb5X2N mbAQcyTnqqfwxaU8YsqSwMFnm0mI6mGP0pGr7iHChpnrvuXkMUGC5OWU4zQjSqwRhJ5n NzUAknljSpXquIpX8QjFgoOY9mnmPEWPi3lTE6cH4WYTKbriz0cQqQgcYlrUQ5Gkp3wf YUCA== X-Gm-Message-State: AMke39n20w4nGkNhE4NzCHhiXlV0J5ztfy2c3LcmDswH8Dz02J0qnDGqxH9FCBrY/sJoueNMTxp8hFc2mQOA3w== X-Received: by 10.200.50.231 with SMTP id a36mr3106923qtb.156.1488551012910; Fri, 03 Mar 2017 06:23:32 -0800 (PST) MIME-Version: 1.0 Received: by 10.12.142.132 with HTTP; Fri, 3 Mar 2017 06:23:32 -0800 (PST) In-Reply-To: <972E3CF5-22BC-4CE0-BD42-29C5382CE90E@gmx.de> References: <972E3CF5-22BC-4CE0-BD42-29C5382CE90E@gmx.de> From: Dave Taht Date: Fri, 3 Mar 2017 06:23:32 -0800 Message-ID: To: Sebastian Moeller Cc: Cake List Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Cake] improving inbound shaping X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Mar 2017 14:23:33 -0000 On Fri, Mar 3, 2017 at 1:22 AM, Sebastian Moeller wrote: > Hi Dave, > > > Last time I tested this I came to the conclusion, that going via ifb and = mirred cost something like 5% shaper sqm performance on ingress. While not = nothing I am not sure this as big a performance issue as you seem to argue. Didn't say double the performance, I said "halve the packet copies". Amdahl's law applies. 5% is a foothold. > Your proposal would improve usability quite a lot though if we could avoi= d the whole ifb-dance... > > To assess the cost of the mirred ifb ingress, I simply instantiated the s= haper for internet download not on ingress of the wan interface, but on egr= ess of the LAN interface connecting the sole testing host, so I believe the= only difference in work for the system should be the ifb/mirred processing= . Well, I plan to fiddle with a new tp-link AC2600 at these higher speeds. That's a dual core arm, and my initial tests with it were quite nice... well, I couldn't crash it, anyway. There's a mcast bug easily fixed in the ethernet driver, the wifi is an ath10k alike that doesn't currently have the make-wifi-fast fixes and I can profile, a bit on it. They're 128 bucks on amazon. https://www.amazon.com/TP-Link-Wireless-Technology-Archer-C2600/dp/B010UR8A= M2 > > On March 3, 2017 7:54:23 AM GMT+01:00, Dave Taht wr= ote: >>As that's the highest cpu user there is, (and the biggest problem I >>have, on comcast, there's 2 sec of latency at 100mbit without shaping: >> >> http://www.taht.net/~d/comcast2/asmiserabledlasever.png >>(more flent data there). >> >>It's always been a daydream to somehow bypass the existing tc_mirred >>facility we use and be able to express: >> >>tc qdisc add dev eth0 ingress cake bandwidth 990mbit >> >>and have that "just work". My hope would be that that would halve >>the packet copies needed (don't know if that's the case in the first >>place)... >> >>When I last looked at it (2+ years ago), that portion of linux was a >>hairball that extended back to the late 90s, and I gave up. >> >>There were a few commits there recently - adding hardware offload >>support for the flower classifier and this one: >> >>commit d2788d34885d4ce5ba17a8996fd95d28942e574e >>Author: Daniel Borkmann >>Date: Sat May 9 22:51:32 2015 +0200 >> >> net: sched: further simplify handle_ing >> >> Ingress qdisc has no other purpose than calling into tc_classify() >> that executes attached classifier(s) and action(s). >> >> It has a 1:1 relationship to dev->ingress_queue. After having commit >> 087c1a601ad7 ("net: sched: run ingress qdisc without locks") removed >> the central ingress lock, one major contention point is gone. >> >> The extra indirection layers however, are not necessary for calling >> into ingress qdisc. pktgen calling locally into netif_receive_skb() >> with a dummy u32, single CPU result on a Supermicro X10SLM-F, Xeon >> E3-1240: before ~21,1 Mpps, after patch ~22,9 Mpps. >> >> >> >> >>-- >>Dave T=C3=A4ht >>Let's go make home routers and wifi faster! With better software! >>http://blog.cerowrt.org >>_______________________________________________ >>Cake mailing list >>Cake@lists.bufferbloat.net >>https://lists.bufferbloat.net/listinfo/cake --=20 Dave T=C3=A4ht Let's go make home routers and wifi faster! With better software! http://blog.cerowrt.org