From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kip Macy Subject: Re: What is machine address? Date: Thu, 16 Sep 2004 11:33:19 -0700 (PDT) Sender: xen-devel-admin@lists.sourceforge.net Message-ID: <20040916113136.A99996@demos.bsdclusters.com> References: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: Errors-To: xen-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: "Ronald G. Minnich" Cc: Steven Hand , Chengyuan Li , xen-devel@lists.sourceforge.net List-Id: xen-devel@lists.xenproject.org How does Plan 9 efficiently handle a large number fragmented memory ranges? FreeBSD can do it, but not well enough to eliminate the PA/MA dichotomy? -Kip On Thu, 16 Sep 2004, Ronald G. Minnich wrote: > > MA = machine address > PA = physical address > VA = virtual > On Thu, 16 Sep 2004, Steven Hand wrote: > > > Physical address = address of a piece of memory used by a guest operating > > system (starting at 0 and going up to the amount of memory you have in > > that particular virtual machine). > > On real machines, PAs == the real hardware. > > On Xen domains, PAs == not real hardware. > Xen actually virtualize physical addresses, so although the PA range in an > OS may be linear and contiguous, the underlying MAs are not. > > At some point I want to fix up Plan 9 to ignore PAs entirely and just VA > and MA, but that's for later. The concept of a PA has no real meaning > anyway at this point, so I see no reason to deal with it. > > ron > > > ------------------------------------------------------- > This SF.Net email is sponsored by: YOU BE THE JUDGE. Be one of 170 > Project Admins to receive an Apple iPod Mini FREE for your judgement on > who ports your project to Linux PPC the best. Sponsored by IBM. > Deadline: Sept. 24. Go here: http://sf.net/ppc_contest.php > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/xen-devel > ------------------------------------------------------- This SF.Net email is sponsored by: YOU BE THE JUDGE. Be one of 170 Project Admins to receive an Apple iPod Mini FREE for your judgement on who ports your project to Linux PPC the best. Sponsored by IBM. Deadline: Sept. 24. Go here: http://sf.net/ppc_contest.php