From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f50.google.com (mail-ed1-f50.google.com [209.85.208.50]) (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 29C173BA8E for ; Sat, 9 Mar 2019 11:03:14 -0500 (EST) Received: by mail-ed1-f50.google.com with SMTP id b20so520185edw.11 for ; Sat, 09 Mar 2019 08:03:14 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:in-reply-to:references:date :message-id:mime-version; bh=o5o9ba8TSKZs7yGJQZTcVWiDkZFBIPchgOB8DdIjv+Q=; b=k0zV3pjKYquBSA8kjBr8sF7KprAJwCMiAkmLsm+7C28PQj8LIMzaKx3CO2jZYMmtju Go0F0chVKQGGDkGyY12fiDINxWq+O34jdheCD8K0Mu7Fu/WeRLMA0+wBgLEh0eSzaBFG sVNUWs/d8KZDJvKtm2gTCpS8s3ZQY90DWjqOwZSuohuh9Cya/vDjkCMvMjotgCgXEs7f Q4Tgf7T4Inf2TEtjhqoTdhj/spS2V2ReNUv9eXIAgTiqfGa8Q1KykPORXSOb6Wl1Oid6 aealgE0SRODmE1xekQybTzWvEJs9tCTe35Y6UKhzR0GJxMoZ0QR2jVfNndOvKEowZ0jo +IPw== X-Gm-Message-State: APjAAAXnp5hOWBLR6SSwjdCHyFfsIlSzjvl6wce0QcI87rO/9yqmQnpc w5RuGKGDE/perSEIZsNBTpmxXw== X-Google-Smtp-Source: APXvYqxq06tNItiDAHRxdM9awpkr9UnpV1fFMH5Bmy+pQgIkJaQAaJz2/hyZzgeZdDHljAXAxKINyw== X-Received: by 2002:a17:906:a445:: with SMTP id cb5mr15653277ejb.72.1552147393190; Sat, 09 Mar 2019 08:03:13 -0800 (PST) Received: from alrua-x1.borgediget.toke.dk (borgediget.toke.dk. [85.204.121.218]) by smtp.gmail.com with ESMTPSA id r48sm3127553edd.87.2019.03.09.08.03.12 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sat, 09 Mar 2019 08:03:12 -0800 (PST) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id EBC5D1804A0; Sat, 9 Mar 2019 17:03:11 +0100 (CET) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Georgios Amanakis , Cake List In-Reply-To: References: X-Clacks-Overhead: GNU Terry Pratchett Date: Sat, 09 Mar 2019 17:03:11 +0100 Message-ID: <87wol83uio.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Cake] profiling using perf 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: Sat, 09 Mar 2019 16:03:14 -0000 Georgios Amanakis writes: > Dear List, > > I made an effort to profile the performance of cake with perf in > openwrt. perf was run on a WRT1900ACS router while downloading > archlinux.iso via torrent in a LAN client. You can find the annotated > sch_cake.c in the attachment as well as a performance histogram of > sch_cake (percentages are relative to sch_cake). Hopefully people can > take a look at it, and see if there are performance concerns. Hmm, nothing immediately jumps out as low-hanging fruit to be harvested. It's not too surprising the 200+-line cake_dequeue() is where most time is spent, since that is where the bulk of the algorithm is implemented. And, well, there's nothing in there that can obviously be removed unless we want to drop features. I guess one could try to make it possible to disable features at compile time; but that carries quite a bit of complexity with it (for one, it needs testing with the combinatorial explosion of possible configurations), so don't think it's realistic. The only exception *might* be a compile time option to turn off those stats that are not needed for the algorithm to run... -Toke