From owner-freebsd-arch Tue Jan 14 19:42:36 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 0D47137B401 for ; Tue, 14 Jan 2003 19:42:35 -0800 (PST) Received: from canning.wemm.org (canning.wemm.org [192.203.228.65]) by mx1.FreeBSD.org (Postfix) with ESMTP id BE93B43F43 for ; Tue, 14 Jan 2003 19:42:34 -0800 (PST) (envelope-from peter@wemm.org) Received: from wemm.org (localhost [127.0.0.1]) by canning.wemm.org (Postfix) with ESMTP id A3A742A89E; Tue, 14 Jan 2003 19:42:34 -0800 (PST) (envelope-from peter@wemm.org) X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4 To: Matthew Dillon Cc: Terry Lambert , "Alan L. Cox" , arch@FreeBSD.ORG Subject: Re: getsysfd() patch #1 (Re: Virtual memory question) In-Reply-To: <200301150316.h0F3GIe8005442@apollo.backplane.com> Date: Tue, 14 Jan 2003 19:42:34 -0800 From: Peter Wemm Message-Id: <20030115034234.A3A742A89E@canning.wemm.org> 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 Matthew Dillon wrote: > > :Also, it gives you a handle to hold data while temporarily unmapped. eg: > :you can implement a small movable mapped window into a larger object. With > :MAP_ANON and /dev/zero, when you unmap the pages they are gone. > : > :Also, we could use one of these beasties as a backing store for malloc(). > :Since the offset is persistent and has a sequence of page offsets it should > :avoid the map fragmentation. > > That is a very interesting idea. fork() would be a problem though. Yes, oops. :-) Cheers, -Peter -- Peter Wemm - peter@wemm.org; peter@FreeBSD.org; peter@yahoo-inc.com "All of this is for nothing if we don't go to the stars" - JMS/B5 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message