From owner-freebsd-arch Wed Jan 22 19:58:11 2003 Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B31AB37B401 for ; Wed, 22 Jan 2003 19:58:10 -0800 (PST) Received: from apollo.backplane.com (apollo.backplane.com [216.240.41.2]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4E62643F13 for ; Wed, 22 Jan 2003 19:58:10 -0800 (PST) (envelope-from dillon@apollo.backplane.com) Received: from apollo.backplane.com (localhost [127.0.0.1]) by apollo.backplane.com (8.12.6/8.12.6) with ESMTP id h0N3w90i017901; Wed, 22 Jan 2003 19:58:10 -0800 (PST) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.12.6/8.12.6/Submit) id h0N3w98H017900; Wed, 22 Jan 2003 19:58:09 -0800 (PST) Date: Wed, 22 Jan 2003 19:58:09 -0800 (PST) From: Matthew Dillon Message-Id: <200301230358.h0N3w98H017900@apollo.backplane.com> To: David Schultz Cc: Peter Wemm , Garrett Wollman , arch@FreeBSD.ORG Subject: Re: getsysfd() patch #1 (Re: Virtual memory question) References: <200301222323.h0MNN7co043532@khavrinen.lcs.mit.edu> <20030123022158.E5F5B2A7EA@canning.wemm.org> <20030123030509.GA52151@HAL9000.homeunix.com> Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG :> > shared memory; I don't see any need for ``semi-anonymous'' shared :> > memory. The garbage-collection problem is already bad enough. :> :> Meanwhile, in the real world, it is exactly what we need at work. :> Anonymous shared memory (MAP_ANON and /dev/zero) isn't good enough. : :I suppose it's too late to argue that the L4 interface would be :sufficient to solve all these problems... Hmm. It's probably a bit overkill for what we need. We would probably want to implement Mach IPC instead (since NetBSD is already working on Mach). But IPC interfaces aren't really the issue here anyway. You still need something to pass (aka a descriptor). While you can pass shared memory around with the Mach interface, it is more designed for the short term shared memory accompanying a message and not really designed for memory objects (which can be larger then a process's VM space). I don't know how L4 deals with passing memory around. -Matt Matthew Dillon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message