From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-x235.google.com (mail-qk0-x235.google.com [IPv6:2607:f8b0:400d:c09::235]) (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 760183B2A4 for ; Wed, 22 Aug 2018 11:10:28 -0400 (EDT) Received: by mail-qk0-x235.google.com with SMTP id f17-v6so1433482qkh.4 for ; Wed, 22 Aug 2018 08:10:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=5AU4gCvWGiXum1LgfNqAM3scM5V+f2KNUFeznkGfBDo=; b=kv3apOpd9RCpDcq5pPBcNIVITqQQ3LG1aQjyR/w8N456Vug+u8rDF6n+9mehWNL5z4 R0J21t7VHNU92UoQp7K7kCjzS/jZhD+fZBwtoOGTSfe7EO0eCCsHR7CZdBaixgY2qxqU 4TJehgcdIlrW9rBMDgZBb8N1/mHmPMwxXHt1Ls8NnnTJ1YYY4vJvomBauPJNDyyir3ND /MP3ONgguSeHpEU7M0BEs0EmTpkvbnBmOjFbiymer2aQsbX8r65QhXlRq5+3KdU50SXW CgFN/W+Bgzp32Urvx2d0DK6q8ayDGv4nPj/YbfLVnat2T/RJNVpujHwJJoypDH4QKE4d G/fw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=5AU4gCvWGiXum1LgfNqAM3scM5V+f2KNUFeznkGfBDo=; b=sRKkhyPPYcIXoHpss5pHUYy0wngmSa0kV3DozGq/J9/aDdZnoSZy5UClZ4/qxslHLj 0EwNUl07LjW3xh1fI2QG1fydzv0zc7LSEHiMVQgBjkddescTdyD19v80msPkkBNUeY0H /O3xvrPbQlfcWKcRREbYEkZpsptcPsWhRxtabItGwOoF8pXArEWk73p2UeYx+C8ETovR 91oN0ghPa2CuqYtvnmtCCn1Gstc9+fNfw9E01ow1CQOS6ZM8XKooXrebE1SnVKUB+oI+ dljRym+pilYxSFERA0xB6osvObIpxvPzNNYj7ybEn7Qc/euUQ3rli4lfHhKg/cHBhzEw X9zQ== X-Gm-Message-State: APzg51CEssL5d6E46coSLiTwtqy51YH8F5KjVNVJ1uIpMiqlAmnqeIQ2 UEfryvSzlgQpOCgX4oo8oYAMlSpLJhR96QmRsfQ= X-Google-Smtp-Source: ANB0VdbYHEEhgmF5cl3YKHfOvJlqplWYNXiSyrfrAwT8zO9K+v1QpoLDbtpI3L/7Q0kCTHDHgTKmYgw2WUQ7PR3+7u8= X-Received: by 2002:a37:8581:: with SMTP id h123-v6mr12440641qkd.237.1534950627963; Wed, 22 Aug 2018 08:10:27 -0700 (PDT) MIME-Version: 1.0 References: <0D0DA11F-AED9-48CE-84DF-B8A380EEFBCD@heistp.net> In-Reply-To: From: Dave Taht Date: Wed, 22 Aug 2018 08:10:14 -0700 Message-ID: To: Pete Heist Cc: Cake List Content-Type: text/plain; charset="UTF-8" Subject: Re: [Cake] 900mbit tbf + fq_codel vs cake on the apu2 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: Wed, 22 Aug 2018 15:10:28 -0000 adding a basic shaper to fq_codel itself is kind of trivial. You need to check if you are shaping https://github.com/dtaht/sch_tart/blob/master/sch_tart.c#L329 Calculate the next start time: https://github.com/dtaht/sch_tart/blob/master/sch_tart.c#L392 and calc the rate in setup and init the watchdog. this was 40% faster than tbf + fq_codel in the good ole days and I sometimes think about just adding it into fq_codel itself, where, in a system already using it elsewhere, keeps the icache hotter as well. I'm going to discard the work in sch_tart and try fiddling with fq_codel again perhaps, but, also over the years, we've found that multiple variables (flows, target, interval) were effectively constants in 99% of cases, and I did want to restore my original work on codel having saner responses to overload that I'd done in earlier versions of cake... dunno. I *personally* need an inbound shaper that cracks 120mbit on mips hardware. ... I hadn't thought about additionally parallelizing the workload (which has problems like adding way more queues than I'd like) much. ... Now, done cleverly, shaping is also parralizable, with an atomic add across this core variable, or a periodic rcu'd merge step of the separate bandwidth clocks running. The "clever" part is that :I've never figured out how two+ instances of a qdisc (being directed by sch_mq) could share a tiny bit of data. There *are* some per-cpu stats rcu'd in qdiscs and filters at this point. and perhaps the per interface (as opposed to per qdisc) stats are rcu'd enough to pull from periodically to compensate. OFFTOPIC: seeing this go by gives me more hope on the rx path than I've had in a while https://lwn.net/SubscriberLink/763056/f9a20ec24b8d29dd/