From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933234AbXCZAgA (ORCPT ); Sun, 25 Mar 2007 20:36:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933235AbXCZAgA (ORCPT ); Sun, 25 Mar 2007 20:36:00 -0400 Received: from smtp-out.google.com ([216.239.45.13]:33848 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933234AbXCZAf7 (ORCPT ); Sun, 25 Mar 2007 20:35:59 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=received:date:from:x-x-sender:to:cc:subject:message-id: mime-version:content-type; b=EGufar7hHPrCGOeAyFont3yUGZKrPHGUDIS+eew0WgVBnTwu3xxjGGvwkDLQTOt6c UR0ICeMAamZ1xnEnbANSQ== Date: Sun, 25 Mar 2007 17:35:46 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Andrew Morton cc: Hugh Dickins , Ingo Molnar , linux-kernel@vger.kernel.org Subject: [patch -mm 1/2] i386: add ptep_test_and_clear_{dirty,young} Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Add ptep_test_and_clear_{dirty,young} to i386. They advertise that they have it and there is at least one place where it needs to be called without the page table lock: to clear the accessed bit on write to /proc/pid/clear_refs. ptep_clear_flush_{dirty,young} are updated to use the new functions. The overall net effect to current users of ptep_clear_flush_{dirty,young} is that we introduce an additional branch. Cc: Hugh Dickins Cc: Ingo Molnar Signed-off-by: David Rientjes --- include/asm-i386/pgtable.h | 25 +++++++++++++++++-------- 1 files changed, 17 insertions(+), 8 deletions(-) diff --git a/include/asm-i386/pgtable.h b/include/asm-i386/pgtable.h --- a/include/asm-i386/pgtable.h +++ b/include/asm-i386/pgtable.h @@ -283,12 +283,23 @@ do { \ } \ } while (0) -/* - * We don't actually have these, but we want to advertise them so that - * we can encompass the flush here. - */ #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY +static inline int ptep_test_and_clear_dirty(struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep) +{ + if (!pte_dirty(*ptep)) + return 0; + return test_and_clear_bit(_PAGE_BIT_DIRTY, &ptep->pte_low); +} + #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG +static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep) +{ + if (!pte_young(*ptep)) + return 0; + return test_and_clear_bit(_PAGE_BIT_ACCESSED, &ptep->pte_low); +} /* * Rules for using ptep_establish: the pte MUST be a user pte, and @@ -305,9 +316,8 @@ do { \ #define ptep_clear_flush_dirty(vma, address, ptep) \ ({ \ int __dirty; \ - __dirty = pte_dirty(*(ptep)); \ + __dirty = ptep_test_and_clear_dirty((vma), (address), (ptep)); \ if (__dirty) { \ - clear_bit(_PAGE_BIT_DIRTY, &(ptep)->pte_low); \ pte_update_defer((vma)->vm_mm, (address), (ptep)); \ flush_tlb_page(vma, address); \ } \ @@ -318,9 +328,8 @@ do { \ #define ptep_clear_flush_young(vma, address, ptep) \ ({ \ int __young; \ - __young = pte_young(*(ptep)); \ + __young = ptep_test_and_clear_young((vma), (address), (ptep)); \ if (__young) { \ - clear_bit(_PAGE_BIT_ACCESSED, &(ptep)->pte_low); \ pte_update_defer((vma)->vm_mm, (address), (ptep)); \ flush_tlb_page(vma, address); \ } \