From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756649AbYH0TCa (ORCPT ); Wed, 27 Aug 2008 15:02:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752412AbYH0TCW (ORCPT ); Wed, 27 Aug 2008 15:02:22 -0400 Received: from gw.goop.org ([64.81.55.164]:38947 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751726AbYH0TCV (ORCPT ); Wed, 27 Aug 2008 15:02:21 -0400 Message-ID: <48B5A4B0.9050308@goop.org> Date: Wed, 27 Aug 2008 12:02:08 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.16 (X11/20080723) MIME-Version: 1.0 To: Nick Piggin CC: Ingo Molnar , Hugh Dickens , Linux Kernel Mailing List , Andrew Morton , Linux Memory Management List Subject: Definition of x86 _PAGE_SPECIAL and sharing _PAGE_UNUSED1 X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org _PAGE_SPECIAL is overloading _PAGE_UNUSED1. Does it really leave _PAGE_UNUSED1 available for other uses, or does it become an exclusive user of that flag. Under what circumstances can they be shared? arch/x86/mm/pageattr-test.c is now using _PAGE_UNUSED1 as the flag used to make sure that huge pages are shattered properly (previously it used _PAGE_GLOBAL). Is that going to clash with _PAGE_SPECIAL? In other words, should we drop _PAGE_UNUSED1 altogether, or at least define how the its different users can coexist? Am I right in supposing that _PAGE_SPECIAL can only be set on user pages? (Also, "SPECIAL" is awfully generic. Was there really no more descriptive name for this?) J