From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from CONVERSION-DAEMON.jhuml3.jhu.edu by jhuml3.jhu.edu (PMDF V6.0-24 #47562) id <0GK800G01BWJN9@jhuml3.jhu.edu> for linux-mm@kvack.org; Tue, 25 Sep 2001 13:43:31 -0400 (EDT) Received: from aa.eps.jhu.edu (aa.eps.jhu.edu [128.220.24.92]) by jhuml3.jhu.edu (PMDF V6.0-24 #47562) with ESMTP id <0GK800G6KBWJBD@jhuml3.jhu.edu> for linux-mm@kvack.org; Tue, 25 Sep 2001 13:43:31 -0400 (EDT) Date: Tue, 25 Sep 2001 13:36:51 -0400 (EDT) From: afei@jhu.edu Subject: Re: Process not given >890MB on a 4MB machine ????????? In-reply-to: <20010925115914.F3437@redhat.com> Message-id: MIME-version: 1.0 Content-type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: "Stephen C. Tweedie" Cc: Joseph A Knapka , "Gabriel.Leen" , "'linux-mm@kvack.org'" List-ID: The current Linux MM design is a 3:1 split of 4G virtual/physical memory. So a process, under normal condition cannot get beyond 3G memory allocated. On Tue, 25 Sep 2001, Stephen C. Tweedie wrote: > Hi, > > On Mon, Sep 24, 2001 at 09:16:58PM +0000, Joseph A Knapka wrote: > > > No. You still only get a maximum of 4GB of -virtual- space per > > process. The machine can address up to 64GB of -physical- RAM, > > but a single process (actually a single page directory) can > > see only 4GB at a time. Sorry :-( > > There are hacks to work around this --- for example, you can set up > large amounts of shared memory and map that on demand when you are > looking up your dataset. However, it's simply not possible for user > space to refer to more than 3GB at once on Linux/Intel. You *must* go > to a 64-bit architecture if you want more than that. > > Cheers, > Stephen > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/