Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750797AbVJJOHK (ORCPT ); Mon, 10 Oct 2005 10:07:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750803AbVJJOHK (ORCPT ); Mon, 10 Oct 2005 10:07:10 -0400 Received: from qproxy.gmail.com ([72.14.204.196]:40502 "EHLO qproxy.gmail.com") by vger.kernel.org with ESMTP id S1750797AbVJJOHJ convert rfc822-to-8bit (ORCPT ); Mon, 10 Oct 2005 10:07:09 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=QO0sIdf5naf6AatxpFaQeDVjaKw2QlGgUkMZIqZPw4hcdB0pfZeOdjrsC/q9nalvtBB7Bxqxs3SqTT4D4Ekhiwlit/5Ag+5+4rnDS9M5dAAq5+tmpzDGa94DtmqVCs77DeAj8D59K3YvGQBBKIO+K51bYkZMzW7Qm/0NVwWBmNo= Message-ID: Date: Mon, 10 Oct 2005 19:37:07 +0530 From: Vivek Kutal To: linux-kernel@vger.kernel.org Subject: ZONE_HIGHMEM query MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 742 Lines: 23 Hello Everyone , All books that I have read say that the concept of ZONE_HIGHMEM is introduced because some architectures cannot directly map memory beyond 896MB (x86). My question is What is direct mapping(does it mean, same virtual address and physical address) and why cant a architecture directly map a particular region in the memory? -- Thanks and Regards Vivek Kutal http://vivekkutal.blogspot.com "Live as if you were to die tomorrow. Learn as if you were to live forever." - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/