From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.17.20]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mout.gmx.net", Issuer "TeleSec ServerPass DE-1" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 42D7B21FCFC for ; Thu, 20 Aug 2015 12:41:25 -0700 (PDT) Received: from hms-beagle-5.home.lan ([87.164.163.27]) by mail.gmx.com (mrgmx102) with ESMTPSA (Nemesis) id 0Lo3IS-1YrG9p2EpM-00g1lq for ; Thu, 20 Aug 2015 21:41:21 +0200 From: Sebastian Moeller Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Message-Id: Date: Thu, 20 Aug 2015 21:41:17 +0200 To: cake@lists.bufferbloat.net Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) X-Mailer: Apple Mail (2.1878.6) X-Provags-ID: V03:K0:YsCFufjyGfFU46PG17yitqe0yus+5WxJRUesHtvEyym4v2vDB63 H5zqWk4ZCDqE6GdElC9aqF3iTXSWpKRVcmBEeBhcTSLlQ33xsQJ6Gb29ZTLC6hb1wdqj+QV Q6krMpLtPZ17p0xzY7+ukfXFQR6A5Ua1f2N8nAUcT6ijdzGtCQaE349Q3myCooa8A9ierTk +Um38SOBLtajIoaM/gyeQ== X-UI-Out-Filterresults: notjunk:1;V01:K0:O5Mhi1a0Y7o=:OcHQucMqunsabqwqde+6DB xLv6oNsYS9qC6VZYEOI9EnCTbGqcVi104FLvc+5fmhrHgFRg5CUsWews5AIj5fAeNepQylBYA VmtSrMSpOFC9A00aYxsD8k5KJwlPWQ59/OryIXAvbYikvkfAhc7Oz5ZMQ0xLtEaHoWZUaQ89u 69WZA5HYw47q7D9bzCIwggAb23xE+Tcbd7Ba0l/J2/kGeKnLdZtibtR3ZrKUq4adRR11EBiwe X1yFEhMASS41RkuKFk0ciFupVZTcOsXd7rt9CEBMNFWVe+gfrTXViDyDOlMNa3HZn6hjSoNCu /xGrEuQ0OIHSaGU7mQifmpjnBfGzvceAPIUPWKzpmCcJ3TKfs3QuX/tyycNX8Tn0xYIrWlUE5 GIbi0z9tiQresmGm/f+pZ/snc5/ETzsRKr2QtYlh6MG7XgNMVmhPOsaUwWTu+esugh59K7ixj SSubIm8NNSR4jx3que5ccNHk2OM9f+Y6IJlujE9kJget/eBn/LqYZBJgcwp9xxEM3xgmEaysG lgN4XgIsNZgG0sSxJnPXdFsMM/NtmSNRf9yvIuBkh5Vb+/a0U9jNQfasCMVbp1EuIl5DduTN9 u0bSiK2RRWWDTXizTS9tNFRN3TR/gNGcoK8c2d88zRr+cPbskcTKtks+btOUrntwQxen9p7zo IznlJId1VaSrzoK9QXo4vktfsnLP0iN7GsBdk/budVTRjcVi4EEPse0byqjaTkRyBZS7P0HAm Qrk0H6RpRFk89bPTASiiHYrHGCQXYULHzVe58g== Subject: [Cake] feature request ;) X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 20 Aug 2015 19:41:49 -0000 Hi Jonathan, I believe we already established that cake will start out with whatever = per packet overhead value the kernel already added for us (skb->pkt_len = or so). Would it be possible to export the maximum of (skb->len - = skb->data_len) seen over the life time of a cake instance somewhere in = the statistics output? Since the kernel rules for pre-adding headers are = a bit opaque this would be really helpful to select the correct per = packet overhead. Say if the kernel added the ethernet header size = already we do not need to use the ethernet keyword, but if it did not we = should, currently the only way to figure this out is to set up an = elaborate shaper and feed it with custom tailored packets and then look = at the reported packet size in the qdsc statistics (if I recall = correctly). It would be so much niched if cake just told us=85 (Case in = point if I establish a shaper on eth0 the kernel helpfully adds the = ethernet header, but if I use pppoe-eth0 which uses eth0 as underlayig = transport the kernel does not add the ethernet header, but it MIGHT add = the pppoe header size (not sure)). And if the max() of that field is too computationally expensive = the first non-zero value would also do... Best Regards Sebastian=