From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933160Ab3HGU3S (ORCPT ); Wed, 7 Aug 2013 16:29:18 -0400 Received: from mail-lb0-f178.google.com ([209.85.217.178]:65128 "EHLO mail-lb0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932350Ab3HGU3R (ORCPT ); Wed, 7 Aug 2013 16:29:17 -0400 Date: Thu, 8 Aug 2013 00:29:14 +0400 From: Cyrill Gorcunov To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, luto@amacapital.net, xemul@parallels.com, mpm@selenic.com, xiaoguangrong@linux.vnet.ibm.com, mtosatti@redhat.com, kosaki.motohiro@gmail.com, sfr@canb.auug.org.au, peterz@infradead.org, aneesh.kumar@linux.vnet.ibm.com Subject: Re: [patch 1/2] [PATCH] mm: Save soft-dirty bits on swapped pages Message-ID: <20130807202914.GO7999@moon> References: <20130730204154.407090410@gmail.com> <20130730204654.844299768@gmail.com> <20130807132156.e97bbcc3d543cf88d5a0997d@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130807132156.e97bbcc3d543cf88d5a0997d@linux-foundation.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 07, 2013 at 01:21:56PM -0700, Andrew Morton wrote: > > > > One of the problem was to find a place in pte entry where we can > > save the _PTE_SWP_SOFT_DIRTY bit while page is in swap. The > > _PAGE_PSE was chosen for that, it doesn't intersect with swap > > entry format stored in pte. > > So the implication is that if another architecture wants to support > this (and, realistically, wants to support CRIU), that architecture > must find a spare pte bit to implement _PTE_SWP_SOFT_DIRTY. Yes? Exactly.