From owner-freebsd-current Fri Apr 24 15:12:58 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id PAA12619 for freebsd-current-outgoing; Fri, 24 Apr 1998 15:12:58 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from narnia.plutotech.com (narnia.plutotech.com [206.168.67.130]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id PAA12610 for ; Fri, 24 Apr 1998 15:12:52 -0700 (PDT) (envelope-from gibbs@narnia.plutotech.com) Received: (from gibbs@localhost) by narnia.plutotech.com (8.8.8/8.7.3) id QAA03142; Fri, 24 Apr 1998 16:09:01 -0600 (MDT) Date: Fri, 24 Apr 1998 16:09:01 -0600 (MDT) From: "Justin T. Gibbs" Message-Id: <199804242209.QAA03142@narnia.plutotech.com> To: Garrett Wollman cc: current@FreeBSD.ORG Subject: Re: Bandwidth throttling etc. Newsgroups: pluto.freebsd.current In-Reply-To: <199804241932.VAA22011@labinfo.iet.unipi.it> <199804242126.RAA10941@khavrinen.lcs.mit.edu> User-Agent: tin/pre-1.4-971204 (UNIX) (FreeBSD/3.0-CURRENT (i386)) Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > What you Really Want is for each interface to manage its own > allocations. When you want to send a packet, you ask the interface > for a buffer, and it gives you one of an appropriate size and shape > that it knows how to transmit efficiently. How do deal with a route change between the time you determine the target interface, ask it to allocate space for you, and construct the packet? The race window becomes much larger if the application asks to pre-allocate space that it will reuse repeatedly to achieve zero copy. Whatever the interface is, it must also handle external memory allocations such as dmaing the payload out of the memory on another device. -- Justin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message