From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.tohojo.dk (mail.tohojo.dk [188.40.53.186]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by huchra.bufferbloat.net (Postfix) with ESMTPS id E2EF6208AAD; Mon, 3 Dec 2012 04:54:42 -0800 (PST) Received: from alrua-laptop.borgediget.toke.dk (unknown [172.16.1.4]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.tohojo.dk (Postfix) with ESMTPSA id 917B51EC0CCA; Mon, 3 Dec 2012 13:54:40 +0100 (CET) Received: by alrua-laptop.borgediget.toke.dk (Postfix, from userid 1000) id 14BDA888; Mon, 3 Dec 2012 13:54:39 +0100 (CET) From: =?utf-8?Q?Toke_H=C3=B8iland-J=C3=B8rgensen?= To: Dave Taht References: <20121123221842.GD2829@linux.vnet.ibm.com> <20121128172058.GB2474@linux.vnet.ibm.com> <20121202230635.GA16359@linux.vnet.ibm.com> <87obib5qf8.fsf@toke.dk> Date: Mon, 03 Dec 2012 13:54:35 +0100 In-Reply-To: (Dave Taht's message of "Mon, 3 Dec 2012 12:31:30 +0100") Message-ID: <87fw3n5m9g.fsf@toke.dk> User-Agent: Gnus/5.130006 (Ma Gnus v0.6) Emacs/24.2 (gnu/linux) MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Cc: Paolo Valente , Eric Raymond , "codel@lists.bufferbloat.net" , "cerowrt-devel@lists.bufferbloat.net" , bloat , paulmck@linux.vnet.ibm.com, David Woodhouse , John Crispin Subject: Re: [Cerowrt-devel] FQ_Codel lwn draft article review X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 Dec 2012 12:54:43 -0000 --=-=-= Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Dave Taht writes: > you have no control. The tx queue rings are flooded before control is > handed back to the fq_codel scheduler. You can get some control back > on a non-BQL driver by reducing the number of tx descriptors > dramatically, but that leads to issues with small vs big packets.... Right, so BQL is pretty much a requirement to get anything worthwhile out of fq_codel? Or is that too strongly put? Without BQL, exactly how much does the driver queue up? I've heard someone say 1000 packets for ethernet, but is that in a different context? E.g. pfifo_fast uses /sys/class/net/*/tx_queue_len for queue length (I think?), but if the qdisc doesn't, does the driver? =2DToke =2D-=20 Toke H=C3=B8iland-J=C3=B8rgensen toke@toke.dk --=-=-= Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iQEcBAEBCAAGBQJQvKELAAoJEENeEGz1+utPE6kH/iEg6ISH1HLXaU2Amn377Aof +Xzu6F2zSy+oZYkwzwwZv5cdeHu6X9zSXB3yIP1gWECeD5RD+M0+H3doNfNp999H bAY4EoOupc9n80Nl0qb1uYgrszD6FzwHaSqnv3S6pKCBSHAbut4wvG/IF0NDf+11 mXOI5hIC+BoNkRKjXw2NriovzZMQ2WasY2idJUjseCl9q//KikxMGhU72dlp2bNJ +1HgnGDWBgy4WERmol14X02+RYHqvRBiiiRtaTash4bGpOhIq7QwEHzkHq0s6K0q RFvkfS/jxS87IY76i3w6++GFZ+3pnMBhmGFLYW18STmgbae6LK2u6kGk+ZVwjJE= =6//J -----END PGP SIGNATURE----- --=-=-=--