From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from web61023.mail.yahoo.com (web61023.mail.yahoo.com [209.73.179.17]) by ozlabs.org (Postfix) with SMTP id 5DE1F67A79 for ; Thu, 14 Jul 2005 06:17:03 +1000 (EST) Message-ID: <20050713201022.69351.qmail@web61023.mail.yahoo.com> Date: Wed, 13 Jul 2005 13:10:21 -0700 (PDT) From: ming lei To: linuxppc-embedded@ozlabs.org MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Subject: double kernel page table entry for the same physical page?! List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 1. In PPC MMU_init sets up kernel page table for all the physical pages available(say size is A) to the virt address starting from PAGE_OFFSET to (PAGE_OFFSET+A). Question: does the linux ever touch this section of page table(virt address from PAGE_OFFSET to PAGE_OFFSET+A) again? like remove or modify one of the entry? 2. In VMALLOC, say we have virt address B(B>PAGE_OFFSET+A), sets up the page table entry for this B to any one of the physical pages. Question: For every physical page, it should already be mapped in #1, but vmalloc maps it again to a virt address higher. Does it mean in kernel page table, we may have two PTE entries pointing to the same physical page, even their virt addresses are different? Last question: If this is true, is this platform implemention specific? Does i386 implemention have same situation? Thanks, Ming ____________________________________________________ Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs