Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755505AbYGVLBQ (ORCPT ); Tue, 22 Jul 2008 07:01:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753382AbYGVLBB (ORCPT ); Tue, 22 Jul 2008 07:01:01 -0400 Received: from ozlabs.org ([203.10.76.45]:36682 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751108AbYGVLBA (ORCPT ); Tue, 22 Jul 2008 07:01:00 -0400 From: Rusty Russell To: Ingo Molnar Subject: Re: [PATCH 1/2] x86: rename PTE_MASK to PTE_PFN_MASK Date: Tue, 22 Jul 2008 20:58:36 +1000 User-Agent: KMail/1.9.9 Cc: Jeremy Fitzhardinge , linux-kernel@vger.kernel.org References: <200807221431.58991.rusty@rustcorp.com.au> <4885774E.3000909@goop.org> <20080722083626.GC2065@elte.hu> In-Reply-To: <20080722083626.GC2065@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200807222058.37130.rusty@rustcorp.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1803 Lines: 45 On Tuesday 22 July 2008 18:36:26 Ingo Molnar wrote: > * Jeremy Fitzhardinge wrote: > > Rusty, in his peevish way, complained that macros defining constants > > should have a name which somewhat accurately reflects the actual > > purpose of the constant. > > Applied to tip/x86/cleanups anyway. Rusty will find out himself how bad > this whole concept of clean and understandable code is, soon enough! I am disgusted with this inappropriate emphasis on clarity over obscurity. It should be pretty clear to everyone here that we can't have both! Fortunately, there is a way to partially rectify the situation. Ingo, please apply. Signed-off-by: Rusty Russell --- include/asm-x86/page.h | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/include/asm-x86/page.h b/include/asm-x86/page.h index 6c84622..4207518 100644 --- a/include/asm-x86/page.h +++ b/include/asm-x86/page.h @@ -10,6 +10,7 @@ #ifdef __KERNEL__ +/* There's something suspicious about this line: see PTE_PFN_MASK comment. */ #define __PHYSICAL_MASK ((phys_addr_t)(1ULL << __PHYSICAL_MASK_SHIFT) - 1) #define __VIRTUAL_MASK ((1UL << __VIRTUAL_MASK_SHIFT) - 1) @@ -19,6 +20,7 @@ #define PHYSICAL_PAGE_MASK (((signed long)PAGE_MASK) & __PHYSICAL_MASK) /* PTE_PFN_MASK extracts the PFN from a (pte|pmd|pud|pgd)val_t */ +/* This line is quite subtle. See __PHYSICAL_MASK comment above. */ #define PTE_PFN_MASK ((pteval_t)PHYSICAL_PAGE_MASK) /* PTE_FLAGS_MASK extracts the flags from a (pte|pmd|pud|pgd)val_t */ -- 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/