Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751064AbWHKJ3w (ORCPT ); Fri, 11 Aug 2006 05:29:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751060AbWHKJ3w (ORCPT ); Fri, 11 Aug 2006 05:29:52 -0400 Received: from mailout1.vmware.com ([65.113.40.130]:21765 "EHLO mailout1.vmware.com") by vger.kernel.org with ESMTP id S1751064AbWHKJ3v (ORCPT ); Fri, 11 Aug 2006 05:29:51 -0400 Date: Fri, 11 Aug 2006 02:15:20 -0700 Message-Id: <200608110915.k7B9FK3v023263@zach-dev.vmware.com> Subject: [PATCH 2/9] 00mm2 pte clear not present.patch From: Zachary Amsden To: Andrew Morton , Andi Kleen , Zachary Amsden , Chris Wright , Rusty Russell , Jeremy Fitzhardinge , Virtualization Mailing List , Linux Kernel Mailing List , Linux MM , ":"@vmware.com, Zachary Amsden X-OriginalArrivalTime: 11 Aug 2006 09:29:49.0549 (UTC) FILETIME=[B12CE9D0:01C6BD28] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2324 Lines: 62 Change pte_clear_full to a more appropriately named pte_clear_not_present, allowing optimizations when not-present mapping changes need not be reflected in the hardware TLB for protected page table modes. There is also another case that can use it in the fremap code. Signed-off-by: Zachary Amsden Signed-off-by: Jeremy Fitzhardinge --- include/asm-generic/pgtable.h | 4 ++-- mm/fremap.c | 2 +- mm/memory.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) =================================================================== --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -110,8 +110,13 @@ do { \ }) #endif -#ifndef __HAVE_ARCH_PTE_CLEAR_FULL -#define pte_clear_full(__mm, __address, __ptep, __full) \ +/* + * Some architectures may be able to avoid expensive synchronization + * primitives when modifications are made to PTE's which are already + * not present, or in the process of an address space destruction. + */ +#ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL +#define pte_clear_not_present_full(__mm, __address, __ptep, __full) \ do { \ pte_clear((__mm), (__address), (__ptep)); \ } while (0) =================================================================== --- a/mm/fremap.c +++ b/mm/fremap.c @@ -39,7 +39,7 @@ static int zap_pte(struct mm_struct *mm, } else { if (!pte_file(pte)) free_swap_and_cache(pte_to_swp_entry(pte)); - pte_clear(mm, addr, ptep); + pte_clear_not_present_full(mm, addr, ptep, 0); } return !!page; } =================================================================== --- a/mm/memory.c +++ b/mm/memory.c @@ -689,7 +689,7 @@ static unsigned long zap_pte_range(struc continue; if (!pte_file(ptent)) free_swap_and_cache(pte_to_swp_entry(ptent)); - pte_clear_full(mm, addr, pte, tlb->fullmm); + pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); } while (pte++, addr += PAGE_SIZE, (addr != end && *zap_work > 0)); add_mm_rss(mm, file_rss, anon_rss); - 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/