From owner-freebsd-current Fri Apr 24 14:09:44 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id OAA01540 for freebsd-current-outgoing; Fri, 24 Apr 1998 14:09:44 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from labinfo.iet.unipi.it (labinfo.iet.unipi.it [131.114.9.5]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id OAA01513 for ; Fri, 24 Apr 1998 14:09:41 -0700 (PDT) (envelope-from luigi@labinfo.iet.unipi.it) Received: from localhost (luigi@localhost) by labinfo.iet.unipi.it (8.6.5/8.6.5) id VAA22011; Fri, 24 Apr 1998 21:32:19 +0200 From: Luigi Rizzo Message-Id: <199804241932.VAA22011@labinfo.iet.unipi.it> Subject: Re: Bandwidth throttling etc. To: benedict@echonyc.com (Snob Art Genre) Date: Fri, 24 Apr 1998 21:32:19 +0200 (MET DST) Cc: kjc@csl.sony.co.jp, current@FreeBSD.ORG In-Reply-To: from "Snob Art Genre" at Apr 24, 98 05:00:53 pm X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > Stevens suggests on p. 297 of TCP/IPv3 that "It appears that an mbuf > cluster should be used sooner (e.g.for the 100-byte point) to reduce the > processing time." > > What are the relative merits of increasing the size of mbufs vs. going > right to clusters? a cluster is 2 KB, an mbuf is 8-16 times smaller. Moreover, a cluster also requires an associated mbuf, so you lose in locality of references, etc. I may be completely wrong, but I'd say that the most effective thing would be to have mbufs large enough to hold the whole packet in most cases. It remains to see how much memory you can afford to waste. cheers luigi -----------------------------+-------------------------------------- Luigi Rizzo | Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it | Universita' di Pisa tel: +39-50-568533 | via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 | http://www.iet.unipi.it/~luigi/ _____________________________|______________________________________ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message