From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755501Ab1JWL7s (ORCPT ); Sun, 23 Oct 2011 07:59:48 -0400 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:45334 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755398Ab1JWL7r (ORCPT ); Sun, 23 Oct 2011 07:59:47 -0400 Date: Sun, 23 Oct 2011 12:59:38 +0100 From: Russell King - ARM Linux To: Catalin Marinas Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v7 13/16] ARM: LPAE: Add identity mapping support for the 3-level page table format Message-ID: <20111023115938.GC17912@n2100.arm.linux.org.uk> References: <1312988619-16804-1-git-send-email-catalin.marinas@arm.com> <1312988619-16804-14-git-send-email-catalin.marinas@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1312988619-16804-14-git-send-email-catalin.marinas@arm.com> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 10, 2011 at 04:03:36PM +0100, Catalin Marinas wrote: > The pmd_addr_end() definition has been removed and the > generic one used instead. NAK - it helps to read code comments. commit c0ba10b512eb2e2a3888b6e6cc0e089f5e7a191b Author: Russell King Date: Sun Nov 21 14:42:47 2010 +0000 ARM: improve compiler's ability to optimize page tables Allow the compiler to better optimize the page table walking code by avoiding over-complex pmd_addr_end() calculations. These calculations prevent the compiler spotting that we'll never iterate over the PMD table, causing it to create double nested loops where a single loop will do. Signed-off-by: Russell King diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h index b155414..53d1d5d 100644 --- a/arch/arm/include/asm/pgtable.h +++ b/arch/arm/include/asm/pgtable.h @@ -374,6 +374,9 @@ static inline pte_t *pmd_page_vaddr(pmd_t pmd) #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd))) +/* we don't need complex calculations here as the pmd is folded into the pgd */ +#define pmd_addr_end(addr,end) (end) + /* * Conversion functions: convert a page and protection to a page entry, * and a page entry and page directory to the page they refer to.