From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751932AbaA2UTD (ORCPT ); Wed, 29 Jan 2014 15:19:03 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:33503 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751126AbaA2UTB (ORCPT ); Wed, 29 Jan 2014 15:19:01 -0500 Date: Wed, 29 Jan 2014 12:18:59 -0800 From: Andrew Morton To: Andrey Vagin Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Cyrill Gorcunov , criu@openvz.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Pavel Emelyanov , Borislav Petkov , Wen Congyang Subject: Re: [PATCH] mm: don't lose the SOFT_DIRTY flag on mprotect Message-Id: <20140129121859.07da0df20daea6a1581e709a@linux-foundation.org> In-Reply-To: <1391025899-25299-1-git-send-email-avagin@openvz.org> References: <1391025899-25299-1-git-send-email-avagin@openvz.org> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 30 Jan 2014 00:04:59 +0400 Andrey Vagin wrote: > The SOFT_DIRTY bit shows that the content of memory was changed > after a defined point in the past. mprotect() doesn't change the > content of memory, so it must not change the SOFT_DIRTY bit. > > This patch does nothing with _PAGE_SWP_SOFT_DIRTY, becase pte_modify() > is called only for present pages. Standard complaint: when fixing a bug, please describe the end-user visible effects of that bug. afaict the effects are minor: snapshotting will save/copy more pages than it needs to, but there will be no malfunction. Hence a -stable backport is unneeded. Agree?