From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Furniss Date: Tue, 25 Jan 2005 12:32:17 +0000 Subject: Re: [LARTC] tail and head drop qdiscs Message-Id: <41F63C51.9050207@dsl.pipex.com> List-Id: References: <1106170939.10019.23.camel@localhost.localdomain> In-Reply-To: <1106170939.10019.23.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lartc@vger.kernel.org vincent perrier wrote: > I think that there are no qdiscs that permit to drop the oldest > frame of a queue when this queue is full, but I would like to > be wrong: > > bfifo drops arriving frames when the max queue length is reached. > > red also drops arriving frames in a more elaborate fashion, with > a drop probability that increases above a limit and becomes > a drop certitude when the max queue length is reached. > > sfq drops "fairly", it piles frames with same (ip source, ip dest, > port source and port dest) and drops a frame from the > biggest pile to favour the smaller flows. > > But I cannot find the qdisc that reacts like a bfifo or red qdisc > but drops the oldest message of the queue when a drop is needed. > > Even better: a qdisc with an autodestruct algorithm for each > frame in the queue that would garantee the "freshness" of > each frame coming out. > > If you know of such qdiscs, please share. > What sort of thing do you want this for? I made a version of esfq head drop for use in specific circumstances. The only other thing I thought head drop generally could be usefull for is a game server, but then maybe a policer would be better than a queue WRT latency. Andy. _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/