From owner-freebsd-current Tue May 4 8:53:19 1999 Delivered-To: freebsd-current@freebsd.org Received: from wall.polstra.com (rtrwan160.accessone.com [206.213.115.74]) by hub.freebsd.org (Postfix) with ESMTP id 7BE8214E9D for ; Tue, 4 May 1999 08:53:17 -0700 (PDT) (envelope-from jdp@polstra.com) Received: from vashon.polstra.com (vashon.polstra.com [206.213.73.13]) by wall.polstra.com (8.9.3/8.9.1) with ESMTP id IAA10036; Tue, 4 May 1999 08:53:12 -0700 (PDT) (envelope-from jdp@polstra.com) Received: (from jdp@localhost) by vashon.polstra.com (8.9.3/8.9.1) id IAA24559; Tue, 4 May 1999 08:53:11 -0700 (PDT) (envelope-from jdp@polstra.com) Message-ID: X-Mailer: XFMail 1.3 [p0] on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: Date: Tue, 04 May 1999 08:53:11 -0700 (PDT) Organization: Polstra & Co., Inc. From: John Polstra To: Dmitry Khrustalev Subject: Re: Any action on PR 10570 ? getting closer to 65K :-( Cc: freebsd-current@FreeBSD.ORG, Warner Losh Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Dmitry Khrustalev wrote: >> It is completely impossible to have 2^32 routes in IPv4. Period. > > Of course not. It is impossible to have 2^32 *host* routes in IPv4. Independent of IPv4, IPv6, or IPvAnything, I make the following claim. Let: P = number of bits in a pointer I = number of bits in the integer type used for a reference counter U = size of addressable unit in bits (8 on most machines). If: U <= P <= I then there is no way in theory or in practice to overflow the reference count. The proof is left as an exercise for the reader. Hint: where will you store that many pointers, and how will you address them? And please don't raise the red herring of code bugs in maintaining the reference counts, because that has never been what this thread is about. John --- John Polstra jdp@polstra.com John D. Polstra & Co., Inc. Seattle, Washington USA "Self-interest is the aphrodisiac of belief." -- James V. DeLong To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message