From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-we0-f171.google.com (mail-we0-f171.google.com [74.125.82.171]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 18E4020228F; Wed, 9 May 2012 09:08:08 -0700 (PDT) Received: by wejx9 with SMTP id x9so653437wej.16 for ; Wed, 09 May 2012 09:08:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=xR/whTwO+feiyhR1xqC010Cvk2Tif/PXHLIEXJ95xis=; b=oZi78AgIUmQchBEaOUaZyb2HD/sCFcSup2MesrCXNnWQnhN/50SG9Y0cEsHIN/g39t 0rMYZnOgruA0T6HLneosXHChmqDt5sSTHPHsBalje9l80a9KHQkUOMDqYpXkgIMW5M/m hCXkFjPtr2ez56ZWW0zHjGziD9RU1Ke79JCpubksmK0IdxAOV/Mm6eURzifHki3Nx375 cXDymb9pWm1nOi3F14r9HgYPJeGnbZvIx/rncHBhv1Z832fifka0TNPSnICFEkhQUC6A 5JAdC0OoTcVuzvAVJpXaWNfmjbgevVFhTr1Lhoi3jehpNaf1fx0D0Jcg0Rn9UBzjFLnp 3giQ== MIME-Version: 1.0 Received: by 10.216.198.14 with SMTP id u14mr419937wen.12.1336579686745; Wed, 09 May 2012 09:08:06 -0700 (PDT) Received: by 10.223.112.66 with HTTP; Wed, 9 May 2012 09:08:06 -0700 (PDT) In-Reply-To: <1336578874.12504.40.camel@edumazet-glaptop> References: <1336368957-17586-1-git-send-email-dave.taht@bufferbloat.net> <1336399043.3752.2318.camel@edumazet-glaptop> <1336571439.12504.27.camel@edumazet-glaptop> <1336578874.12504.40.camel@edumazet-glaptop> Date: Wed, 9 May 2012 09:08:06 -0700 Message-ID: From: Dave Taht To: Eric Dumazet Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: codel@lists.bufferbloat.net, bloat , =?ISO-8859-1?Q?Dave_T=E4ht?= Subject: Re: [Codel] [PATCH v12] codel: Controlled Delay AQM X-BeenThere: codel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: CoDel AQM discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 May 2012 16:08:10 -0000 On Wed, May 9, 2012 at 8:54 AM, Eric Dumazet wrote= : > On Wed, 2012-05-09 at 08:47 -0700, Dave Taht wrote: >> Doing (or leveraging) the timestamp on actual ingress to the system, >> rather than entrance to the exiting queue, more accurately will >> compensate for overall system loading and the overhead of traversing >> 3+ pages of function calls to get it from the >> entrance point to the exit, and should result in 'tighter' results. > > > Most qdiscs dont need this timestamp, so it would add overhead in fast > path. > > Also, the delta between 'entering' qdisc layer and entering codel > enqueue is almost a constant for a given qdisc/filter setup, and less > than one us : > > If you really want to take it into account, replace 'target 5000us' by > 'target 5001 us' In the special case of routers and switches with codel on by default, I think it would help. I can code it up.... > > --=20 Dave T=E4ht SKYPE: davetaht US Tel: 1-239-829-5608 http://www.bufferbloat.net