From owner-freebsd-hackers Fri Jul 5 23:14:42 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 69D3737B400 for ; Fri, 5 Jul 2002 23:14:39 -0700 (PDT) Received: from harrier.mail.pas.earthlink.net (harrier.mail.pas.earthlink.net [207.217.120.12]) by mx1.FreeBSD.org (Postfix) with ESMTP id 078C743E09 for ; Fri, 5 Jul 2002 23:14:39 -0700 (PDT) (envelope-from tlambert2@mindspring.com) Received: from pool0156.cvx40-bradley.dialup.earthlink.net ([216.244.42.156] helo=mindspring.com) by harrier.mail.pas.earthlink.net with esmtp (Exim 3.33 #1) id 17Qion-0006Yo-00; Sat, 06 Jul 2002 02:13:18 -0400 Message-ID: <3D268A53.146EBBF6@mindspring.com> Date: Fri, 05 Jul 2002 23:12:35 -0700 From: Terry Lambert X-Mailer: Mozilla 4.7 [en]C-CCK-MCD {Sony} (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Darren Pilgrim Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: How does swap work address spacewise? References: <20020705113532.GA11273@atrbg11.informatik.tu-muenchen.de> <20020705133515.GA295@HAL9000.wox.org> <20020705133837.GA513@HAL9000.wox.org> <20020705234126.GA12183@atrbg11.informatik.tu-muenchen.de> <3D2640A7.3EA2236B@pantherdragon.org> 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 Darren Pilgrim wrote: > If RAM + swap can be more than 4GB, how does FreeBSD address swap on a > 32-bit machine? Does the kernel internally use a wider address space > with some kind of translation to 32-bit space for programs and hardware > that can't handle 64-bit addresses or does it not map swap into the > address space at all, instead using it as a kind of "offline" storage > for pages not in use? Does the Alpha port handle swap the same way? KVA + UVA = 4G KVA is per system... but UVA is per process. Therefore you can have as much as you want, so long as it's per process, and you only run processes one at a time (which is what kernels do ;^)). -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message