From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from localhost (sanket@localhost) by mailhub.cdac.ernet.in (8.11.4/8.11.4) with ESMTP id g35BRug18836 for ; Fri, 5 Apr 2002 16:57:59 +0530 (IST) Date: Fri, 5 Apr 2002 16:57:56 +0530 (IST) From: Sanket Rathi Subject: How CPU(x86) resolve kernel address Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: linux-mm@kvack.org List-ID: I read all about the memory management in linux. all thing are clear to me like there is 3GB space for user procee and 1GB for kernel and thats why kernel address always greater then 0xC0000000. But one thing is not clear that is for kernel address there is no page table, actually there is no need because this is one to one mapping to physical memory but who resolve kernel address to actual physical address how CPU(X86) perform this task because when we do DMA we have to give actual physical address by virt_to_phys() so what is the mechanism by which CPU translate kernel address into physical address ( Somewhere i heard that CPU ignore some of the upper bits of address if so then how much bits and why). Thanks in advance --- Sanket Rathi -- 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/