From owner-freebsd-hackers Tue May 15 6:10:50 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from salmon.maths.tcd.ie (salmon.maths.tcd.ie [134.226.81.11]) by hub.freebsd.org (Postfix) with SMTP id 28B6837B422 for ; Tue, 15 May 2001 06:10:46 -0700 (PDT) (envelope-from dwmalone@maths.tcd.ie) Received: from walton.maths.tcd.ie by salmon.maths.tcd.ie with SMTP id ; 15 May 2001 14:10:44 +0100 (BST) Date: Tue, 15 May 2001 14:10:44 +0100 From: David Malone To: raviprasad20@netscape.net Cc: freebsd-hackers@freebsd.org Subject: Re: Memory organization in case of large amount of data (jumbo grams) Message-ID: <20010515141044.A98820@walton.maths.tcd.ie> References: <3C3AC794.368D5BEE.9513E96F@netscape.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <3C3AC794.368D5BEE.9513E96F@netscape.net>; from raviprasad20@netscape.net on Tue, May 15, 2001 at 08:15:56AM -0400 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Tue, May 15, 2001 at 08:15:56AM -0400, raviprasad20@netscape.net wrote: > My doubt is whether freebsd uses the normal mbuf & clusters in case > of large amount of data (like jumbogram in ipv6 or the maximum ipv4 > datagram size of 65536 bytes)? FreeBSD provides two standard types of storage (mbufs and mbuf clusters) for network use, but data can be stored in other ways too - some of the gigabit ethernet drivers define jumbo clusters of size 8kB, allowing jumbo eithernet packets to be recieved in a single chunk. In general the idea of the mbuf system is that no copies of the data need to be done, so even if the data is a little fragmented it shouldn't be a big problem. (Some ethernet cards may need the data to be unfragmented before sending, but most of the good cards shouldn't. Also the important size here is not so much the IPv6 of IPv4 maximum sizes, but the size of the MTU on the medium on which you are tramsmittin.) David. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message