From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: <200101251959.OAA27790@mal-ach.watson.ibm.com> To: Dan Malek cc: Roman Zippel , mgreer@mvista.com, linuxppc-dev@lists.linuxppc.org Subject: Re: CONFIG_HIGHMEM on PPC In-Reply-To: Message from Dan Malek of "Thu, 25 Jan 2001 14:47:43 EST." <3A7082DF.CD7E8B61@mvista.com> Date: Thu, 25 Jan 2001 14:59:06 -0500 From: David Edelsohn Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: >>>>> Dan Malek writes: Dan> Heh....64Gbyte is nothing, just a few more bits beyond 32....you Dan> don't need 64-bits for this. In fact, I had a revelation last Dan> night where I thought we could even do this quite transparently Dan> on PowerPCs with VSIDs or even context registers, anything that Dan> implictly gives us a few more bits of virtual address. Later Dan> on that..... Yes, that is the exact purpose of the PowerPC addressing model. While one user context is limited to 32-bit addresses, the system can map a larger physical address range into the process's virtual address space. The process even could handle this with OS cooperation using overlays. David ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/