From owner-freebsd-hackers Thu Aug 2 17:35:44 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from smtp4ve.mailsrvcs.net (smtp4vepub.gte.net [206.46.170.25]) by hub.freebsd.org (Postfix) with ESMTP id 0461537B401 for ; Thu, 2 Aug 2001 17:35:38 -0700 (PDT) (envelope-from babkin@bellatlantic.net) Received: from bellatlantic.net (client-151-198-135-40.nnj.dialup.bellatlantic.net [151.198.135.40]) by smtp4ve.mailsrvcs.net (8.9.1/8.9.1) with ESMTP id AAA61216444; Fri, 3 Aug 2001 00:35:26 GMT Message-ID: <3B69F1CD.F8798A3E@bellatlantic.net> Date: Thu, 02 Aug 2001 20:35:25 -0400 From: Sergey Babkin X-Mailer: Mozilla 4.7 [en] (X11; U; FreeBSD 4.0-19990626-CURRENT i386) X-Accept-Language: en, ru MIME-Version: 1.0 To: tlambert2@mindspring.com Cc: craig , freebsd-hackers@FreeBSD.ORG Subject: Re: How to visit physical memory above 4G? References: <002701c11aed$ae1b98a0$051a0a0a@fd.com> <3B68F190.AB04ACB3@mindspring.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Terry Lambert wrote: > > This basically means that the memory is useless as a DMA target > or source for disk controllers or gigabit ethernet cards, and is > pretty useless for swap, if you ever have to copy from one section > to another (e.g. for IPC, SYSV shared memory, mmap'ed files, VM, > or buffer cache, etc.). For the PCI cards supporting the 64-bit addresses you can. (Note that in PCI support of the 64-bit bus is independent of the 64-bit address space, the 64-bit addresses can be multiplexed over a physically 32-bit bus). -SB To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message