From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933235AbXCZAgG (ORCPT ); Sun, 25 Mar 2007 20:36:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933258AbXCZAgG (ORCPT ); Sun, 25 Mar 2007 20:36:06 -0400 Received: from smtp-out.google.com ([216.239.45.13]:33856 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933235AbXCZAgE (ORCPT ); Sun, 25 Mar 2007 20:36:04 -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:in-reply-to: message-id:references:mime-version:content-type; b=t+rMMYJns24GkvA0pFGWXStqBAS3BEwDWx//yggV+hReAC3WDZV/pqIqpicA6O4kL 7tmExn6lh1WgALIz3mtlg== Date: Sun, 25 Mar 2007 17:35:54 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Andrew Morton cc: Hugh Dickins , linux-kernel@vger.kernel.org Subject: [patch -mm 2/2] smaps: use ptep_test_and_clear_young In-Reply-To: Message-ID: References: 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 Use arch-specified ptep_test_and_clear_young() to clear the pte accessed bits for /proc/pid/clear_refs. This avoids a race condition if a pte is modified between pte_mkold() and set_pte_at(). Cc: Hugh Dickins Signed-off-by: David Rientjes --- fs/proc/task_mmu.c | 5 +---- 1 files changed, 1 insertions(+), 4 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -277,10 +277,7 @@ static void clear_refs_one_pmd(struct vm_area_struct *vma, pmd_t *pmd, continue; /* Clear accessed and referenced bits. */ - if (pte_young(ptent)) { - ptent = pte_mkold(ptent); - set_pte_at(vma->vm_mm, addr, pte, ptent); - } + ptep_test_and_clear_young(vma, addr, pte); ClearPageReferenced(page); } pte_unmap_unlock(pte - 1, ptl);