From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from max.phys.uu.nl (max.phys.uu.nl [131.211.32.73]) by kvack.org (8.8.7/8.8.7) with ESMTP id OAA01320 for ; Mon, 1 Feb 1999 14:34:25 -0500 Received: from mirkwood.dummy.home (root@anx1p7.phys.uu.nl [131.211.33.96]) by max.phys.uu.nl (8.9.1/8.9.1/hjm) with ESMTP id RAA29983 for ; Mon, 1 Feb 1999 17:12:30 +0100 (MET) Date: Mon, 1 Feb 1999 16:59:22 +0100 (CET) From: Rik van Riel Subject: Re: Large memory system In-Reply-To: <19990130083631.B9427@msc.cornell.edu> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Daniel Blakeley Cc: linux-mm@kvack.org List-ID: On Sat, 30 Jan 1999, Daniel Blakeley wrote: > I've jumped the gun a little bit and recommended a Professor buy > 4GB of RAM on a Xeon machine to run Linux on and he did. After he > got it I read the large memory howto which states that the max > memory size for Linux 2.2.x is 2GB physical/2GB virtual. The > memory size seems to limited by the 32bit nature of the x86 > architecture. The Xeon seems to have a 36bit memory addressing > mode. Can Linux be easily expanded to use the 36bit addressing? Just today there was a patch on linux-kernel with a patch that allows you to use the top 2 GB as a RAM disk or something like that. You can use that for swap and to mmap() stuff on. I think this could be quite useful for large simulations and stuff like that. 36-bit addressing is a bit difficult at the moment, but undoubtedly someone will code up something like that for Linux 2.3 (maybe the prof could let some (under)graduate student do this as a major project?). succes, Rik -- If a Microsoft product fails, who do you sue? +-------------------------------------------------------------------+ | Linux Memory Management site: http://humbolt.geo.uu.nl/Linux-MM/ | | Nederlandse Linux documentatie: http://www.nl.linux.org/ | +-------------------------------------------------------------------+ -- To unsubscribe, send a message with 'unsubscribe linux-mm my@address' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://humbolt.geo.uu.nl/Linux-MM/