From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 26 Oct 2000 13:52:45 -0200 From: "Rodrigo S. de Castro" Subject: ptes flags in compressed cache Message-ID: <20001026135245.B19100@linux.ime.usp.br> 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: Hello, I am working on a compressed cache for 2.2.16 and I am currently in a cache with no compression implementation. Well, at this step, I gotta a doubt of how can I mark the pages (actually, ptes) that are in my cache and neither present in memory nor in swap. This is essential when I have a page fault, and this page is not present in memory. It is (in a normal kernel) assumed to be in swap, but it can, now, be in my cache. In order to mark the pte, I first thought of a flag (in the style of _PAGE_*), and I defined _PAGE_COMPRESSED with 0x200, because all before were used. However, I got into a big trouble. An address like 0xe00 is a valid swap address, and returns true when I and it with 0x200. Thus, my question is: is there an offset in swap address that allows me to use this part of address to put a flag of mine in that free space? And, even more importante, do you have any other idea to solve that? Maybe a better solution, that does not depend on swap implementation and any future change would not screw my current solution up. I don't have any idea of what might have been changed on 2.4, so that's the main reason of asking you and be trying to avoid possible troubles! :-) PS: There's a simple page of my project. Give a look at: http://tutu.ime.usp.br []'s -- Rodrigo S. de Castro Computer Science undergraduate student - University of Sao Paulo -- 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.eu.org/Linux-MM/