From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrea Arcangeli <andrea-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
Subject: Re: [patch 2/6] mmu_notifier: Callbacks to invalidate
	address	ranges
Date: Tue, 29 Jan 2008 17:20:04 +0100
Message-ID: <20080129162004.GL7233@v2.random>
References: <20080128202840.974253868@sgi.com>
	<20080128202923.849058104@sgi.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Cc: Nick Piggin <npiggin-l3A5Bk7waGM@public.gmane.org>,
	Peter Zijlstra <a.p.zijlstra-/NLkJaSkS4VmR6Xm/wNWPw@public.gmane.org>, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org,
	Benjamin Herrenschmidt <benh-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>, steiner-sJ/iWh9BUns@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>,
	kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, daniel.blueman-xqY44rlHlBpWk0Htik3J/w@public.gmane.org,
	Robin Holt <holt-sJ/iWh9BUns@public.gmane.org>, Hugh Dickins <hugh-DTz5qymZ9yRBDgjK7y7TUQ@public.gmane.org>
To: Christoph Lameter <clameter-sJ/iWh9BUns@public.gmane.org>
Return-path: <kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
Content-Disposition: inline
In-Reply-To: <20080128202923.849058104-sJ/iWh9BUns@public.gmane.org>
List-Unsubscribe: <https://lists.sourceforge.net/lists/listinfo/kvm-devel>,
	<mailto:kvm-devel-request-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org?subject=unsubscribe>
List-Archive: <http://sourceforge.net/mailarchive/forum.php?forum_name=kvm-devel>
List-Post: <mailto:kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
List-Help: <mailto:kvm-devel-request-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org?subject=help>
List-Subscribe: <https://lists.sourceforge.net/lists/listinfo/kvm-devel>,
	<mailto:kvm-devel-request-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org?subject=subscribe>
Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
List-Id: kvm.vger.kernel.org

On Mon, Jan 28, 2008 at 12:28:42PM -0800, Christoph Lameter wrote:
> Index: linux-2.6/mm/fremap.c
> ===================================================================
> --- linux-2.6.orig/mm/fremap.c	2008-01-25 19:31:05.000000000 -0800
> +++ linux-2.6/mm/fremap.c	2008-01-25 19:32:49.000000000 -0800
> @@ -15,6 +15,7 @@
>  #include <linux/rmap.h>
>  #include <linux/module.h>
>  #include <linux/syscalls.h>
> +#include <linux/mmu_notifier.h>
>  
>  #include <asm/mmu_context.h>
>  #include <asm/cacheflush.h>
> @@ -211,6 +212,7 @@ asmlinkage long sys_remap_file_pages(uns
>  		spin_unlock(&mapping->i_mmap_lock);
>  	}
>  
> +	mmu_notifier(invalidate_range, mm, start, start + size, 0);
>  	err = populate_range(mm, vma, start, size, pgoff);

How can it be right to invalidate_range _before_ ptep_clear_flush?

> @@ -1634,6 +1639,8 @@ gotten:
>  	/*
>  	 * Re-check the pte - we dropped the lock
>  	 */
> +	mmu_notifier(invalidate_range, mm, address,
> +				address + PAGE_SIZE - 1, 0);
>  	page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
>  	if (likely(pte_same(*page_table, orig_pte))) {
>  		if (old_page) {

What's the point of invalidate_range when the size is PAGE_SIZE? And
how can it be right to invalidate_range _before_ ptep_clear_flush?

-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2008.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/